The Devil's Heart
by owlcroft
Summary: A man like Sherlock Holmes is considered a hero by some and a right bastard by others. But he also proves the adage that one can tell at least as much about a man from his detractors as one can from his friends. Here, Sherlock solves two crimes and one mystery, and inadvertently reveals a little about his enemies, a little about his friends, and quite a bit about himself.


_The authors thank Dr. D.P. Lyle, MD., for his generous and invaluable assistance with their technical questions. Read Dr. Lyle's very cool novels and non-fiction forensics-for-writers books, available from the usual suspects._

The Devil's Heart

by

Owlcroft and Paula Douglas

"Hurry up, Annora, before Mum calls." Ten year-old Tevin Roundhay impatiently toed a well-worn football and watched as his little sister fussed about the goal post.

"I _am_," she called back, and added something else, but her words were drowned by the roar and clatter of a Thameslink shuttle as it raced past not 25 yards away. The train flashed red and blue beyond the bare branches of a narrow strip of leylandii and buckthorn, what the town council was pleased to call a greenbelt. The children were quite used to the noise, however, as only the thin line of scrubby trees and the railroad's chain link fencing separated the back garden of their row house from the tracks.

Their makeshift goal was nothing like as large as a real football standard. Made out of scrap wood found around the neighbourhood and discarded sheets secured by plastic tie wraps that served for netting, it had been cobbled together by Tevin with some assistance from his little sister. Annora had found the construction of the goal to be largely beyond her skill level, but, not to be outdone by her brother, her elder by two years, she insisted on doing her part to keep it in trim. At the moment that involved replacing three of the tie wraps where the sheet corners had frayed and come loose. The whole arrangement stood at the back of the narrow lot between the Roundhays' house and the last home in the row of a dozen other residences.

The children considered themselves fortunate to live in one of the very few houses in the row with such a gap between it and its neighbour. Their home's front and back gardens were far too small and confined to make satisfactory football grounds, and on cold, misty, early spring days like this, with the ground sodden and inclined to turn into a muddy mess with the least foot traffic, they were forbidden to stray off the walkways in any case. Their mother was adamant that modest means and squalor need not be inextricably linked, and she insisted on a clean house. That made the concrete pad between their home and the next an incomparable blessing.

"Come _on_!" Tevin called when the train had passed. "Before Mum has lunch on."

Annora gave a last tug on the final tie wrap, sprinted back to her brother, and looked expectantly up at him.

"'Bout time," he growled, feigning annoyance. "Now look. You're already pretty fair at dribbling and passing and you'll kick those other girls' arses on conditioning."

Annora giggled at the word 'arses,' and said, "I'm telling Mum."

"Shut up. You need more power and accuracy on scoring," Tevin said. He scooped up the ball, tossed it in his hand, then tucked it under his arm. "Three steps," he said, holding up a corresponding number of fingers by way of illustration.

Annora never took her eyes from him.

"The higher you bring your kicking leg up behind you, the better. You get more power. Keep your ankle locked when you kick. Like this," he said, "not this," and demonstrated the difference between a stiff and floppy ankle. Annora copied him, frowning with concentration.

"Keep your other knee bent a little," Tevin said. "The way you point the foot you're standing on is the way the ball will probably go. Get it?"

She nodded.

"Right, then," he said, and set the ball on the ground. "Watch." He demonstrated, sending the ball sailing into the center of the net, where it billowed the sheet and rattled the fence behind, then bounced out again. Annora ran forward and collected the ball, dribbling it back to her brother with admirable skill for her age.

"Lean forward," Tevin said, as she positioned herself for her own try. "If you lean forward you get more power. If you lean back you get more height. Right now you want power."

Annora bit her lower lip, attacked the ball, and managed to implement two of her brother's tips. Her strike had power and follow-through but lacked any sort of accuracy, flying not toward the goal but at the neighbour's screened side door. Toward it and through the glass.

Both children stared at the devastation and finally Tevin broke the stunned silence. "Jesus Christ, Nora," he said, "the goal post's down there."

"Don't call me Nora," she shot back, and punched him in the arm. Being ticked off at her brother was better than crying, which she was trying very hard not to do just then.

"You'll make starter for sure if you can kick the ball around a corner like that. Mum's gonna be pissed now."

"Shut up, Tevin," she snapped.

"Well, go get the ball," Tevin said.

"No way!"

"_You_ kicked it into the house."

Annora bit her lower lip again, this time to keep from crying.

Tevin sighed theatrically. "Never mind," he said. "I'll do it."

Annora hung back, wavering between relief and shame, as he started toward the neighbours' front door. Their neighbours, middle-aged twin brothers who never left the house except to put out the bins, were widely believed by the neighbourhood's pre-teen population to eat children. Yet Annora knew that she was responsible for the broken glass. Both her mum and Grandpa Peabody were adamant that anyone could make a mistake, but that decent, honorable people freely admitted their errors and did what they could to repair them, whereas what her grandfather called 'deviants' did not. Annora craved her grandfather's approval, so she didn't struggle long with the decision.

She hurried after Tevin. "I'll do it," she insisted, pushing past him and hopping determinedly up the four crumbling concrete steps to the front door. No one answered the bell. She tried again. Still nothing. Knocked, then knocked a bit louder. "Maybe they're not home," she said hopefully.

"You git," Tevin said. "They're always home. Mum says they haven't left the house for years. Come on."

He led the way back to the side door and peered through the gap left by the broken glass. The hallway was dark, as was the main room beyond, although he thought he could make out the flickering of a television. He heard voices but decided that those came from the telly as well. He tapped on the aluminium door frame. "Mr. Tregennis? It's Tevin Roundhay. From next door? We're really sorry, but _my sister_ broke the glass on your door." He paused, listening, but there was no movement from inside the house. "Mr. Tregennis?" Nothing. Many times the children had heard the brothers fighting-they had loud, frequent rows-but now only the faint sound of the television came from within.

"Now what?" asked Annora.

"Stay here," Tevin said.

"What, you're not going in there?" Annora was aghast.

"How else do you expect to get the ball back, stupid?" Tevin asked scornfully. "Stay here and shut up."

Annora knew that it was her job to get the ball, but ringing the bell and copping to the window was one thing; trespassing inside the scary neighbours' house was something else entirely. Besides, taking care of his little sister was Tevin's job. Mum and Grandpa and even Tevin himself were quite firm on that point. Still. There were those rumours... "What if it's true that they eat-"

"Shut _up_," Tevin hissed. He tried the door handle, but it was locked, so he carefully reached inside around the broken glass and after a bit of fiddling found the latch. Inside a sharp, unpleasant, vaguely chemical smell filled his nose. Tevin felt instinctively that it was unsafe, but he was only going to be there for a second. Just long enough to get the ball. The brothers habitually kept their blinds drawn and the drapes shut, so although it was a gloomy day it took a bit of blinking in the dark before his eyes adjusted enough and he spotted the ball where it had rolled to the end of the side entry hall. Tevin took a determined breath, felt a tingling sensation in his nose and mouth, his heart banged frantically in his chest, and then everything went black.

ooooo

John used his elbows to shut off the taps in the exam room sink and reached for the paper towels. He'd just tossed them when the nurse tapped the open door and stuck her head in.

"Mrs. Roundhay and the kids are here," she said.

"Great," John said with a pleased smile. "Thanks. Send them right in."

The Royal Free Hospital's walk-in clinic was a first-come, first-served affair, but when the staff brought word to Doctor Watson that the Roundhays had 'a bit of an emergency,' as Mrs. Roundhay had put it, he'd left instructions that she was to be shown in immediately upon arrival.

Superhero schedule permitting, John tried to volunteer at the free clinic at least one Saturday each month. While the work was generally light and almost without exception routine, it kept him in practice and got him out of the flat to pursue his own affairs. Not for the world would he trade his life with Sherlock Holmes, but all the same his well-developed sense of independence required these occasional respites from Sherlock's dominant personality and all-consuming focus on their cases, compelling though they were.

His work at the Free Clinic also put him into irregular contact with Major Arthur Peabody, a Korean War veteran and one of John's favorite patients. One of his favorite people, if it came to that. The Major's daughter, Sarah Roundhay, a divorced bookkeeper for a City bakery, also took advantage of the hospital's free clinic for her kids' sake. A somewhat harassed but conscientious single mum, she took great care of her kids' physical well-being, but what John approved of even more were her high standards for their education. The Roundhay children were well-mannered and bright, the sort of kids he could talk to almost as though they were adults. He envied them, in a way: They were fond of each other, and the boy was protective of his little sister, the way John believed firmly that a big brother should be. The way he'd tried to be for Harry.

Mrs. Roundhay stepped into the room, just managing to keep the children in check, but the instant they spied John they skipped past her.

"Doctor John!" Annora cried, running up and throwing her arms around him.

Tevin was more circumspect-blokes didn't hug each other-but he was just as pleased to see their friend the Doctor and extended his hand like a gentleman. "Hello, Doctor John," he said politely.

Tevin appreciated the way Doctor John treated him and Annora like grown-ups, never talking down to them and always making a point of asking after their grandfather. He was great friends with Grandpa, although nothing like as old. They'd both been soldiers, but Tevin wasn't quite clear on which war they'd been in or even whether they were in the same war. He was very urgent to know whether Grandpa had killed people when he was a soldier, but Mum said it would be unforgivably rude to ask, and Tevin knew that the same rule applied even more forcefully to Doctor John. Besides, he thought it unlikely that someone as gentle and kind as Doctor John could ever hurt someone, even in a war.

For her part, Annora idolized Doctor John. She wanted very much to be a veterinarian when she grew up, and he encouraged her without reserve-and Tevin, too, for that matter-to study hard in school and to concentrate on math and science. She liked to have his blessing on that count because some of her friends thought it was silly and gross to study bugs and dirt and read all the time, and she could always reply loftily to them, "Doctor John says science is a _good_ thing."

Hugs and handshakes dispensed with, John closed the door and said, "Come in. Sit down. Sit down. How's your grandpa?"

"Dad's doing great," Mrs. Roundhay said.

"He's taking us to dinner at Red Lobster tomorrow night," Annora announced happily.

"You tell him I said hello," John said to her with a smile, then turned to her mum. "Now. What's all this about an emergency?"

Tevin looked at the floor and Annora elbowed him. "Tevin fainted," she said.

"Shut _up_," Tevin whispered fiercely, and elbowed her back.

"Fainted?" John said with a frown. He looked at Mrs. Roundhay. "How long ago did this happen?"

"Around lunchtime," she said. "About half twelve."

John glanced at his watch: It was just after three now.

"Tell me exactly what happened."

"Annora kicked the football through the neighbours' side door and broke it," Tevin said, glancing accusingly at Annora.

"Through the door," John repeated. "Through the glass?"

"Yes," said Annora, "but it was an accident."

"Impressive," John said, and Annora looked pleased.

"We tried to ring the doorbell, but no one answered," Tevin said, "so I told her to wait and went inside. It smelled all ooky, but I could see where the ball was, so I started to go get it and then I woke up and I was laying on the floor."

"Ooky," John said. "What do you mean by 'ooky'?"

Tevin shrugged. He didn't really have a good explanation for the smell and it was hours ago. "It was kind of...It was like...It was ooky," he finished lamely.

"Did you smell it?" John asked Annora.

"Uh-huh," she said, nodding.

"Don't be rude, Annora," Mrs. Roundhay put in. "Say 'yes' or 'no,' not 'uh-huh.'"

"Yes," Annora said. "It was kind of tangy and made my mouth buzz."

"But it didn't make you faint, or make you dizzy?" John asked.

"No," said Annora. "I held my breath. And I put my shirt over my nose. Then I helped Tevin get out of the house."

"Clever girl," John said.

"At first I didn't realize how serious it was," Mrs. Roundhay said, "and I went to the neighbours to apologize about the door, but when I got back he said he had a headache and felt a little dizzy. That's when they finally told me about the fainting." She frowned at them. "If I'd known that of course I wouldn't have worried about apologizing. We'd have come straight away."

"Of course," John said. "Well, let's look under the hood. Hop up here, Tevin" he said, and patted the exam table. "Sounds perfectly normal," he decided when he'd listened carefully to the boy's heart. "How's your headache now?"

"Fine," Tevin said.

"What do you think it was?" Mrs. Roundhay asked worriedly. "Carbon monoxide?"

John shook his head. "Probably not," he said. "It's odourless and it's heavier than air. If Tevin started to recover when he was lying on the floor it's likely that whatever he was breathing was less concentrated there, so I'd rule out carbon monoxide." He considered. "That's assuming that the source of the smell caused the fainting. What about the people who live there? How are they?"

Mrs. Roundhay shook her head almost imperceptibly and gave him a meaningful look.

John took the hint. "Tell you what," he said to the kids. "Why don't I take a look at you guys now, and then your mum and I will talk, okay?"

Mrs. Roundhay nodded an assent.

John added checks of his blood pressure, respiration, eyes, and ears to Tevin's exam, then repeated the inspection with Annora, finishing with a check of her blood pressure. "Do you know what this is called?" he asked her as he held up the cuff, tubing, and bulb.

"Huh-uh," she said. "I mean, 'no.' But it's to do blood pressure. Right?"

"Exactly," John said. "It's got a long name. It's a sphygmomanometer."

She giggled. "No way."

"Way. This is the cuff," he said, showing her. "This is the bulb, and this is the dial where we read your blood pressure." He wrapped the cuff on her arm.

She tried to repeat the word. "Sphyg..."

He repeated it more slowly: "Sphyg...mom...anometer."

"Sphygmom..."

"...anometer."

"Sphygmomanometer."

"That's it," John said with a smile. "I know doctors who can't say it right. They just call it 'the blood pressure cuff.'"

Annora grinned proudly. "Sphygmomanometer." She repeated it to herself several times to cement the word in her brain. She was delighted with this information, which she would repeat to impress her grandfather _and_ the stupid girls at school.

With the exams concluded Mrs. Roundhay issued strict orders to Tevin to keep an eye on his sister, and both kids departed for the lobby to wait for her. Annora skipped out holding her brother's hand and repeating "sphygmomanometer" to herself as they went.

"Okay," John said when they'd gone. "What happened next door?"

"Well, I went over to apologize and to offer to pay for the glass, but no one answered. I could hear the telly on and-"

"Who lives there?"

"Two brothers. George and Owen Tregennis." She hesitated, still twisting the straps of her purse. "I should have thought they'd have heard all the commotion by then, but they never answered, so I went inside. They were dead, Doctor Watson."

ooooo

"John," Sherlock said in greeting as John reached their landing.

The detective was where John expected to find him-at the kitchen table-and the kitchen table was as John expected to find it-covered with Sherlock's latest science project. This one appeared at a glance to involve an inordinate number of six-inch wood swabs, but John was a long way ahead of his flatmate: He'd stopped for Chinese takeaway to obviate the need to eat around Sherlock's experiment. They spent a good many Saturday nights this way, with Sherlock peering at disgusting things on the kitchen table and John perforce eating over the sink.

"You stopped at Plum Garden," Sherlock noted before John even came into view.

"Yeah," John said, not bothering to ask how he knew. "Got you some Bird of Paradise. Hungry?"

"Maybe tomorrow," Sherlock said absently. He wrote something on an adhesive label in his elegant hand and applied the label to an evidence bag containing a single swab.

"Well, it'll be in here," John said, opening the refrigerator door, "by the-" Goddammit. "Are these fetal mice?" No answer. "Sherlock."

"Hmm?"

"These are mice."

"Yes."

"Fine. Your Chinese is by the mice."

Mention of the mice reminded Sherlock of something, and he glanced up. "Have you seen the stick blender?"

ooooo

John leant against the counter and ate his own order out of the carton as he watched Sherlock work. Swabs, evidence bags, adhesive labels, and covered petri dishes littered the table. After a few minutes John realized that the swabs weren't tools for the experiment: They _were_ the experiment. "That the Shadow case?" he asked.

"Mm."

"Going okay?"

"Probably," Sherlock said, without looking up.

His self-satisfied expression told John that he was pleased with the progress of his work, but he offered nothing else by way of explanation. John, however, was quite used to this. Sherlock's penchant for drama and his delight in John's admiration carried on unabated, and he evidently believed that the surest way to gain that admiration was to keep John in the dark as long as possible and then produce a 'voila' moment carefully calculated to amaze and astound him.

John had long ago given over fretting about being kept guessing in this way, but he considered it an unnecessary expense of effort on Sherlock's part: If anything, knowing the individual links that comprised Sherlock's chain of reasoning made his conclusions even more impressive to John. The drama was part of Sherlock's nature, however, and nothing would induce him to change. Then, too, the fact that he sought John's approval fed John's own vanity, so ultimately the arrangement suited them both.

"Interesting thing at the clinic today," John noted.

"First time for everything," Sherlock replied.

"Divorced mum with two kids-"

"Boring."

"That's _not_ the interesting part."

"Ah."

"Her neighbours were found dead this afternoon."

Flicker of interest. "Murdered?"

"Not sure."

"Still not interesting." Sherlock glanced briefly up at John-this was his idea of teasing-but when John just hiked his eyebrows and sighed he stopped interrupting.

"Her kids were playing ball, yeah? Ball gets away from them and goes through the side door of the neighbours' house. Through the glass. Kid knocks on the door, doesn't get an answer, so he lets himself in to get the ball, and _bam_."

Sherlock carefully rolled the tip of a swab onto the agar of a petri dish. "Saving time, 'bam' is slang for...?"

"Well, it's contextual, but I meant, 'kid keels over unconscious.'"

"Saw the bodies and fainted."

"Nope. Kid never saw them. Got a whiff of something strange inside the house and just blacked out. Started to revive a bit after he hit the floor."

"Not a gas leak, then," Sherlock said.

"I know."

"Putrefaction?"

"Nope. The guys died between half eleven last night and noon today."

Contempt: "That's the best the police could narrow it down?"

"No, that's all the mum knew. She hasn't talked to the police except to phone them initially. She found the bodies when she went over to apologize for the kids wrecking the door. Said if the kids hadn't accidentally kicked the ball through it there's no telling how long it might have been before someone found the bodies. They never went out. Doors and windows locked from the inside," John added, with emphasis.

"Suicide," Sherlock decided. "Boring."

"Or murder-suicide."

"Still boring."

John shrugged, forked in a little more sweet & sour chicken, and watched Sherlock mutter over his work. He individually bagged and labeled three more swabs, replaced the lids on three open petri dishes, labeled them as well, then sat back in his chair.

"You said, 'the guys.'"

"Yeah. Twin brothers. Shut-ins. Lived together but hated each other. Fought constantly. That's how she knew they were still alive last night: She heard them having a row during a programme she was watching on telly."

Sherlock smiled. "Interesting."

"That's what I said."

"Yes, but you don't know _why_ it's interesting."

"Because whatever made the boy sick didn't affect his mother and sister, but it probably killed the brothers."

"Nope."

"Why's it interesting, then?"

"Because they were brothers." Full-on grin now. "Come on. Get your coat."

ooooo

On the way to Brent Terrace, a fifteen minute cab ride from Baker Street, Sherlock phoned Lestrade.

"It's me," he said, when Lestrade picked up. "Nine Brent Terrace. Twin brothers found dead this afternoon. Sound familiar?" Pause. "Who's working it?" Longer pause. "John asked me to look into it," he said, and ended the call.

"No, I didn't," John said.

Sherlock shrugged. "Effectively."

"What did he say?"

"He remembers the case but wasn't there himself. Says the ME tends to think that the deaths were due to natural causes, but they also think it's odd that both men died within an hour or two of each other."

"'Odd'."

"Mm. Anderson's on site, but the rest have already packed up and left. Lestrade's going to call the security detail to let them know we're coming."

John nodded: Until the ME determined whether or not foul play was involved the scene would remain active and not be released to the family or the estate. Until that release was made official a marked patrol car and uniformed officers would be assigned to maintain the integrity of the scene.

The expected police car stood parked parallel to the street across from Nine Brent Terrace. Their cab stopped behind it. Sherlock didn't bother acknowledging the patrolmen-two bored-looking female cops-and headed straight for the house. John instructed the driver to wait, then gave a wave to the policewomen. He'd seen them around before, although he didn't know their names, and they'd obviously gotten the word from Lestrade because the one in the driver's seat gave a bit of a nod when she saw him.

An ambulance and a criminalist's van stood parallel parked on the house side of the street and police tape stretched across the front and sides of the sparse lawn. Sherlock stopped at the tape for an overview of the site and John joined him there a moment later.

Their breath fogged in the still air. A fine mist reduced the visibility to just a mile or two, and moisture dripped from the black tree branches. Even if the low overcast hadn't prematurely darkened the day the house would have had an air of gloom: a seedy, run-down brown brick row house with peeling paint on the dry-rotting window trim. Desiccated weeds sprouted from the cracks of the concrete walk leading to the front door. Two lichen-speckled concrete planters on the front doorstep held the brown, brittle remains of geraniums at least a couple of years old, and dirt spilled from the broken end of one planter, down the cracked concrete steps and across the landing. The front lawn was less lawn than a field of mud dotted with clumps of brown grass and broadleaf weeds.

Sherlock slipped under the tape and paced up the walk to the front door while John skirted the lawn and stopped to wait for him in the center of the concrete pad between the Tregennis house and its neighbour: He would be in Sherlock's way if he followed, and there was almost certainly nothing discoverable on the exterior of the house that Sherlock wouldn't find on his own.

Sherlock easily made out the tracks of the neighbour children where they cut across the lawn to the front door, as well as the partial treads of their trainers in the dirt spilled from the planter. These overlaid two partials of a much larger print from a waffle-soled shoe, one going toward the house and one overlying it and going from it.

He could see no evidence that the door had been forced. Nor had the four ground floor windows, which were obviously painted closed, and in fact he could see no evidence of anyone other than the children having been in the yard. Waffle Soles had kept strictly to the walkway.

Movement at the corner of his eye made him glance to his right. A woman was peering from a side window of the neighbouring house, and she obviously recognized John. Sherlock wasn't surprised when a moment later she hurried out the side door, wiping her hands on a tea towel, and crossed the concrete pad to greet John. His patient, Mrs. Something. Harmless. Sherlock turned away and continued his inspection.

"Doctor Watson," Mrs. Roundhay said with a bright smile. "Hello. I didn't really think you'd come."

"Mrs. Roundhay," John said, shaking her hand. "I wasn't sure, either. How's Tevin doing?"

"He's fine. _Seems_ fine."

"Headache hasn't returned?"

"No, and I think he's getting tired of me taking his pulse."

John smiled and they both watched Sherlock as he moved toward the far corner of the house, inspecting the ground as he went.

"That's him, isn't it?" Mrs. Roundhay whispered.

John cocked his head. "'Him'?"

"Your detective."

"My detective," John agreed, amused.

"I thought he'd be taller," she said.

"Disappointing, isn't he?"

She laughed. "Sorry," she said. "It's just-I've never seen a celebrity in person before."

John didn't know what to say to that.

"He thinks George and Owen were murdered, doesn't he?"

"Well," John said carefully, "he thinks there's something-" he could not possibly say 'interesting' "-_puzzling _about the circumstances."

"What does he think it is?"

"He hasn't said. He likes to get all the facts first, before he draws any conclusions, so he wanted to come have a look."

"It's scary, isn't it?" she said, and when he looked questioningly at her added, "That they might have been murdered. I know it's not the best part of town and crimes happen everywhere, but..."

"It's hard when they happen so close to home."

"Yes, exactly."

Sherlock disappeared around the corner.

"Do you think there will be any lasting effects?" Mrs. Roundhay asked. "From the air, I mean? Whatever it was?"

John shook his head. "I doubt it."

"Why do you think it only affected Tevin?"

John wasn't completely sure about that. "Well," he said, "houses aren't air-tight, but if there was enough of whatever it was to make him sick when he opened the door, maybe by the time you got there it had dissipated enough so that you weren't affected. Annora said she held her breath, and that's probably why it didn't affect her. I don't think you need to worry about him," he added. "His pulse and blood pressure were completely normal this afternoon. The blood tests will take a couple of days, but I don't expect them to show anything wrong either. I'll call you if there's a problem, but if you don't hear anything from me by Friday he's all clear. But I don't expect I'll be calling."

She smiled gratefully at him. "Thank you so much, Doctor Watson. And thank you again for seeing us on such short notice. I was so worried. Dad always says you're the best doctor in town, and I suppose if something awful had to happen it's lucky it happened when you were available to see us."

John opened his mouth to demur, but the sound of Sherlock pushing through the weeds and scrub behind the fence that enclosed the back garden caught their attention, and they turned to watch his progress. The sagging board-on-board fence extended right up against the tree line, and he had to push several of the loose boards up to get past them.

It was apparent to him that no one had scaled the fence at any point, and the windows in the back of the house had the same painted-closed appearance as the others. The back garden was if anything shabbier than the front, with a long-abandoned flower bed in the back corner, separated from the grass by a border of bricks that had been halved and set at an angle. It was choked with several years' growth of weeds, but a few legitimate perennials that still competed successfully with the invaders were just beginning to push clear of the cold mud.

His exterior inspection complete, Sherlock ambled toward John and his patient, eyeing first John and then the woman. John gave no sign that he was interested in her as a romantic prospect, but then she was a patient, and he was adamant about the moral hazards of fraternization. He stood now with his hands clasped behind his back and feet shoulder width apart, his weight evenly balanced over each foot: An open, friendly stance, but then he did the same when he stood over a body talking to the ME, so Sherlock assigned it no importance. On the other hand, everything about the woman's body language-hands at her sides, frequent eye contact, idiot smile-told him that if John did overcome his professional scruples he wouldn't risk a rebuff. As Sherlock drew closer and she turned to face him her dilated pupils and flushed cheeks confirmed him in that opinion, and he also read bookkeeper in the City, right-handed, enjoyed baking, kept a budgerigar. Boring.

"Sherlock," John said as he stopped before them, "This is Sarah Roundhay. She and her kids are patients of mine, and her father is Major Peabody."

John said this as though Sherlock should know who Peabody was, and no doubt John had told him-probably more than once, knowing John-but Sherlock hadn't retained the information.

"Mrs. Roundhay, this is my friend, Sherlock Holmes."

"Hello, Mr. Holmes," she said. "Such a pleasure to meet you." He might not be as tall as she'd assumed from the telly and the papers, but in person and at this distance his pale eyes, intensity, and unconventional good looks made an impressive and somewhat intimidating combination.

Sherlock noticed that her blush deepened as she extended her hand to him, and he'd never actually seen anyone bat her eyes before now. Interesting. Potentially useful. "Mrs. Roundhay," he said warmly, taking her hand in his and holding it just a fraction longer than necessary. "I'm delighted to meet you. John's told me all about your lovely family." John's blink of surprise at the display of geniality didn't escape Sherlock, either. "So very sorry to hear about your neighbours."

"Oh," she said, brushing her hair away from her face and hooking it behind her ear, "I didn't know them well. At all, really."

"Ah. Still, it must have been a terrible shock finding them dead."

"Oh, yes. No one answered the door when I went over to apologize for the kids breaking the glass, but I could hear the telly on, so I went inside." She shook her head. "One was in his arm chair and the other was on the floor."

"You don't know which one?"

"No. They were identical twins, and they almost never left the house. I really never saw them except when one would put the bins out, but I didn't even know them well enough to tell them apart."

"Two brothers living together," Sherlock mused. "They must have been quite devoted to each other."

"Well, if they were," she said, "they did a good job hiding it. You hardly ever saw them but you could always hear them. Fighting day and night. Always screaming at each other. Even in winter, when everything's shut up, I could hear them."

Sherlock tutted. "What about the odor the children noticed?" he asked. "Could you smell it?"

She shook her head. "It's hard to describe, and it was pretty faint."

"Did it smell like decomposition?" He already knew that it didn't, but perhaps prompting would get her to elaborate to the point of saying something useful.

"No, nothing like that," she said. "More like...chemicals, maybe?"

"And did you feel as though you were going to faint as well?"

"No. Never. Well, not until I saw George and Owen. I went straight back home and called the police. To be honest I was so scared when I realized they were dead that I got out of there as fast as I could. It was so creepy in that house. They never opened the windows; it was all dark with the curtains drawn and everything locked up so tight and just the light from the telly." She produced a tissue and blew her nose. "I'm just so glad the kids didn't realize that they'd walked into a house with dead people."

"Quite right," Sherlock agreed. "Once they started experimenting they'd never stop."

"What?"

John shifted his weight from one foot to the other: Annoyed. "Or...not," Sherlock said. Time to change the subject. "When was the last time you heard the brothers fighting?"

"Oh, just last night," she said, back on firm ground. "I remember because I was watching a National Geographic programme. About meerkats."

Sherlock glanced at John.

"Like a mongoose."

"Ah."

"I like educational telly. 'Never stop learning,' you know." She paused and looked at Sherlock a little hopefully, but his expression of polite expectation never wavered. "Well, the programme started at eleven, and it was about halfway through when they started in again next door. I couldn't make out what they were saying because the window was closed, but that's the last time I heard anything from them."

"I imagine they must have socialized a good deal?" Sherlock said. "Probably had pretty regular visitors?"

"No, never," she said at once. "No one ever stopped in, unless you count the service for the groceries and the druggist, and a lot of times they'd just leave the orders on the front step. There was a service for their lawn, too, not that you can tell."

"Well, thank you very much for your time, Mrs. Roundhay," Sherlock said. "We won't keep you standing about in the cold any longer." He took her hand in both of his and smiled down at her.

The slight tilt to Sherlock's head cemented John's growing suspicion into certainty: He was making a clinical inspection of Mrs. Roundhay's pupil response to his touch and proximity, for God's sake. This was more than John could decently support. It was also apparent to him that Mrs. Roundhay would have been delighted to stand about in the cold maintaining the contact, but she'd die of exposure before that paid off for her. With a warning glance at Sherlock he cleared his throat. They understood each other perfectly, but there was no penitence in Sherlock's expression when he let go of Mrs. Roundhay's hand.

"Well. Mrs. Roundhay," John said, and she turned to look at him. "Thanks for coming out. You be sure to call me if Tevin needs anything, and tell your dad I said hello."

When the screen door closed behind her they turned toward the Tregennis house and John said, "Remember when we decided that sometimes you shouldn't use words?"

"Yes. Why?"

"'It's a good thing her kids didn't find the bodies because they'd still be experimenting on them'?"

Sherlock sniffed. "You're a doctor. Tell me you never poked dead things with a stick."

"Yeah, frogs. Not people, for God's sake."

"Lack of opportunity."

"Sense of decency."

Sherlock eyed the broken side door as they entered the house but didn't see anything noteworthy about it: Like the front door, it showed no signs of having been forced or jimmied, and except for the football-shaped hole in the glass it was unremarkable. Inside the gloom persisted, although the investigators had turned on what appeared to be every light in the house.

Sherlock stopped just inside the door, closed his eyes, and slowly drew in a lungful of air. John himself couldn't detect anything strange the way Mrs. Roundhay and the kids described it, but the house had the stale, musty odor of a place that badly needed an airing: The smells of mildew, body odor, and cooked food mingled unpleasantly.

Sherlock exhaled and opened his eyes. "How did the boy describe the odor?"

"'Ooky,'" John said.

Sherlock raised his eyebrows, and John shrugged. "Not a clue," he admitted.

"Must be genetic," Sherlock said discontentedly. "'Ooky.' 'Chemical.'"

"I don't think she was paying much attention, what with finding the dead people," John said.

"No one pays much attention," Sherlock groused. "Dead people or not."

He led the way down the short side hall. On their right a doorway led into a galley-style kitchen, which, like the hallway, also opened on to the main room. Sherlock glanced into the kitchen as they passed it but continued on into the living room. Two well-worn armchairs in a greasy, yellow-and-green plaid fabric stood more or less in the center of the room, their backs to the kitchen and facing the telly, which was against the far wall on a low-slung, 1970's-vintage entertainment center with a peeling, fake wood grain vinyl coating. A large picture window looked out over the muddy back garden. A Thameslink train clattered past as they paused in the doorway. To the left of the living area, at the front of the house, the main entry separated a formal dining room on the left from a smaller, more intimate sitting room, re-purposed as office, on the right.

The bodies of the two brothers lay on plastic sheets in the center of the main room. The sheets would retain any trace evidence that might be dislodged from the bodies during transport to the morgue. Two ME assistants waited nearby with gurneys and body bags. Already they had placed paper bags over the victims' hands and secured them with rubber bands, another standard step to ensure the preservation of any trace evidence.

Phillip Anderson was packing his equipment and samples into black cases when he saw them and scrambled to his feet. "Sherlock. John," he said, grinning with real pleasure as he advanced to shake their hands.

John was still struck by the difference in Anderson's attitude toward them since Sherlock's return from the dead. His distrust and dislike of Sherlock had made him all too eager to believe the worst about the detective, and he'd been instrumental in helping Moriarty engineer Sherlock's public disgrace-inadvertently, perhaps, but effectively all the same. On the other hand, his genuine remorse and guilt over Sherlock's apparent resulting suicide drove him to make some unfortunate personal decisions that ultimately cost him his job. The subsequent revelation that Sherlock had faked his death in order to ensure Moriarty's downfall provided Anderson with something like redemption, and, suitably chastened, he had spent an inordinate amount of time since then sincerely trying to make up for his former malice.

He also wrongly credited Sherlock for his eventual reinstatement in his old job. In fact Mycroft had seen to that. John-and Sherlock, to the extent that he'd thought about it, which wasn't much-knew that Anderson was more useful to Mycroft when gainfully employed by the police and that Mycroft used Anderson, like he used everyone else, when it was convenient for him. In particular, he used the fictile Anderson to spy on Sherlock. This never failed to rankle John, but he granted Mycroft's genuine concern for his little brother and Sherlock himself generally tolerated the practice with a certain amount of indifference, if not equanimity.

As for Sherlock's approach to Anderson, that remained as loftily cool as ever, but since worshipful obsequiousness rather than hostility now characterized Anderson's attitude, Sherlock at least refrained from savaging him. The adoration didn't affect Sherlock any more deeply than the hostility had, but it did make Anderson more helpful and easier to work with, so Sherlock didn't disapprove of the change.

"Phil," John said politely.

"Anderson," Sherlock said with Olympian insouciance.

"What are you guys doing here?" Anderson asked, and then answered his own question. "You think these guys were _murdered_."

Sherlock frowned. "Why are you whispering?"

Anderson reddened. "Sorry," he said, and in his normal voice asked, "Why do you think they were murdered?"

"Do I?"

"Well, you wouldn't be here if they'd died of natural causes. You won't leave the flat for 'anything less than an eight,' remember?"

Sherlock didn't answer, but it occurred to him that this might be what John meant by 'boundary issues.'

"Unless you knew the victims?" Anderson asked, misinterpreting his silence. "Oh, I'm sorry. I didn't-"

"No," John said, taking pity on him because Sherlock obviously wasn't going to. "No. We didn't know them. The neighbour who found them is a patient of mine. She mentioned it. Just thought we'd take a look."

He was about to add a _pro forma_, "If that's okay," but Anderson said eagerly, "Absolutely. Everyone's done. I was about to release the bodies to the ME. Hold up a sec, guys," he added, addressing the technicians.

He dove into one of the kits, produced a fistful of latex gloves, and offered them to John and Sherlock. This was another big change from a few years ago, John reflected. Back then if

Anderson thought it would help Sherlock solve a case he wouldn't have sold him a glove for a hundred pounds.

Anderson pointed to the body nearest the picture window. "George Tregennis. Age 58. Twin brother Owen," he added, pointing to the body on the left. "The scene's been processed, as you can see. Owen was found face down on the floor a few feet from the chair and George was still in the armchair. Listen," he added apologetically, "I have to get this stuff back to the lab. They're really cracking down on us about overtime."

Sherlock feigned sympathy. "Do you mind if we look around a bit?" he asked.

"Of course not," Anderson said at once. "Absolutely. I'll let the security detail know that you'll be a while. Is there anything else I can do?" He looked hopefully from one to the other.

"Actually," Sherlock said, "if you could spare a few evidence bags and some swabs..."

"Of course," Anderson said, delighted to help. He produced a generous handful of small plastic evidence bags and an unopened packet of sterile swabs, then hovered until Sherlock said, "Overtime."

"Oh, right." Anderson gathered up his kits and hurried out.

John waited until the door closed before giving Sherlock a wry look. "'May I trouble you for a swab?'" he said with exaggerated prissiness. "It was less disgusting when he hated you."

Sherlock just smiled in reply and was about to pull on his gloves when they heard the side door open again and Lestrade's voice called, "Sherlock? John?"

"Living room," John called back, and when the detective appeared said, "I thought this wasn't your case."

"It wasn't," Lestrade said. "But it wasn't a murder case before. Now it is."

John wondered whether Lestrade knew something that they didn't. "Why do you say that?"

"Well, you two are here, for a start."

"He's got a point," John said to Sherlock. "Even Phil figured out that you wouldn't investigate deaths by natural causes."

"Phil?"

"Anderson."

"Oh."

"So come on," Lestrade said briskly. "What makes you think these deaths are suspicious?"

John took him through it, explaining about , how her son apparently succumbed to the strange odor in the house, and Sherlock's interest in the deaths when he learned that the victims were brothers.

"What 'strange odor'?" Lestrade asked. "I don't smell anything. None of the SOCOs who were here earlier have said anything about it."

"We don't know," John said. "There wasn't anything when we got here, either, but then we've only been here a couple of minutes. We were just about to get started," he added, holding up his pair of gloves.

"Oh, well, off you go, then," Lestrade said. He knew better than to impede their work.

After donning the gloves John knelt and examined each body in turn. He'd long ago given up trying to draw the kinds of inferences and deductions that Sherlock could from the things he saw at crime scenes, and instead relied on his own established skill set for his contributions. Sherlock's knowledge of anatomy was extensive but unscientific, and while his store of medical information had increased greatly through his association with John he was no doctor, and John's medical 'big picture' had helped more than once to steer him toward the solution to a case.

John saw no obvious external signs that pointed to a cause of death. In fact, the bodies and their immediate vicinity were noteworthy mainly for what they lacked: no injuries, no signs of violence, no blood, no vomit or other fluids. Knowing that the brothers had been alive at 11:30 the night before helped him estimate the time of death, however: Rigor took twelve hours to completely set in, lasted approximately another twelve, and then relaxed over the course of twelve more. The rigor in these bodies had reached a moderately advanced stage, and knowing that they'd still been alive around midnight the night before suggested something in the eight to ten hour range.

"Anything?" Sherlock asked, meaning, Can you determine the cause of death?

John shook his head and stood up. "Nothing obvious at this stage. It's going to take the autopsy to get that. Of course, if it was environmental asphyxia that won't be evident on autopsy, so we might have to wait on toxicology. An airborne toxin could cause arrhythmia, I suppose, but that won't show up at autopsy, either. It's strictly an electrical phenomenon."

"Remind those of us who aren't doctors or geniuses," Lestrade said. "Arrhythmia is..."

"Premature heartbeat," Sherlock said.

John nodded. "When the heart beats outside the normal sinus rhythm. It's an umbrella term for several conditions, but that's the essence of it."

"But that wouldn't kill them both at the same time, would it?" Lestrade asked.

"If whatever caused the odor killed them, then yes," Sherlock said.

"I'd put time of death at between ten and noon for both of them," John said. "Probably still warm when Mrs. Roundhay walked in. They died within an hour or so of each other, if not simultaneously."

"Not simultaneously," Sherlock said in a decided tone.

"No?"

"George was in the chair. Owen was on the floor, at least two strides away from his chair. Even from here you can see the marks his feet left on the carpet before the police moved the body. What does that suggest to you?"

John hesitated and Lestrade looked a little blank.

"Come on," Sherlock said impatiently. "No one else was in the house. There are no weapons, no signs of violence-"

"Maybe he just fell out of the chair when he died," Lestrade offered.

Sherlock shook his head. "No. Look," he said, pointing. "The police have trampled most of the evidence, of course, but you can still see the impressions in the carpet where his feet were."

They couldn't see anything of the sort.

"He got a good two strides away from the chair-"

"Before he was overcome," John finished, as realization dawned. "He was trying to get away from whatever killed his brother."

Sherlock looked triumphantly at Lestrade.

Lestrade looked more confused than ever. "But what killed them?"

"Whatever was in the air," Sherlock said.

"Which was?"

Sherlock hesitated fractionally. "I don't know," he admitted.

It was never easy for him to say that, and he didn't look happy about it now, but John knew him well enough to know that he'd already formed at least one plausible theory, unwilling though he might be to share it so early in the investigation.

Sherlock pulled on his gloves and took his turn inspecting the bodies: hair, skin, hands, pockets, clothing. Owen: on-line porn addict, insomniac. George: allergies, pipe smoker, on-line gambling addict. In Owen's left front trouser pocket he found a small paper pouch, and although both John and Lestrade were watching him, he successfully palmed it and slipped it into his own pocket.

Besides his own chair each brother had his own side table. A tea cosy and ceramic mug with a few millimetres of muddy brown liquid stood on Owen's; George's held an ashtray, a book of matches, and a plastic wrapper containing four pipe cleaners. Sherlock leant over the mug and sniffed. Tea. Taylor's Yorkshire Original Red. Original Red and...something else he couldn't identify. He ran a swab around the inside of the mug, then bagged and pocketed the swab.

Even with all the available lights in the house on, the room wasn't particularly well-lit, so he withdrew his torch, knelt down with his face near the floor, and shone the light at an oblique angle across the matted shag carpeting. The police had made the usual shambles of most of the footprint evidence, but he peered under the skirts of the chairs and around the bodies, as well as the chairs themselves. Three used pipe cleaners lay under George's table, along with an accumulation of pipe dottles. Sherlock carefully smelt the dottles, to the amusement of the CSI technicians watching him, then bagged and labeled several discrete samples and pocketed them. The pipe itself lay several feet away, almost under the big picture window that looked out onto the back garden.

Still on his hands and knees and utterly oblivious to the impatience and scornful stares of the two technicians, he crawled over to the pipe and examined it thoroughly with his glass, then sniffed gingerly at the material in the bowl. He knew well over two hundred brands of tobacco ash by scent and by sight, and neither sense helped him identify this tobacco. Interesting. An irregular trail of the stuff was distributed from the chair to where the pipe lay, suggesting to him that the pipe had been thrown-possibly when George thrashed or convulsed as he died-to its current location. He bagged and labeled samples of these dottles, as well as a generous portion of the material in the pipe's bowl. The police could make do with the remainder.

The television's remote control also lay nearby, its back cover off and just one battery remaining inside, and the wall to the left of the window bore a small but recent gouge to show where it had been thrown, possibly during last night's row.

Sherlock stood, peeled off the gloves, and waved dismissively at the technicians.

John gave them an apologetic smile. "Thanks for waiting," he said. "We appreciate it."

"Yeah, fooled me," one of the men replied sarcastically.

"What do you think?" Lestrade asked.

"Last night at half eleven the neighbour heard the brothers fighting. That-" pointing to the shattered television remote "-either happened during the row, or precipitated it. George died first, or at least was the first to be affected by whatever was in the air. Owen realized the danger, tried to escape." He pointed to the body as the technicians lifted it into the black bag. "That's as far as he got."

Lestrade couldn't make much of that. "Okay...?"

"We'll know more once we've seen more," Sherlock said. "John? Kitchen?"

"Got it," John said, and turned at once to see what he could find there.

"Inspector," Sherlock said. "The office. Owen was an insomniac. Enjoyed internet porn to unhealthy excess. George spent most of his time gambling on line. I expect a look through their computers will provide a few more details. You might even find something I can use."

Lestrade might have asked how Sherlock knew about the brothers' online habits, might have resented being assigned a task at his own crime scene by a civilian. Years ago, he would have. Now he knew better, so he willingly headed for the office, where he went through each brother's computer in turn. He could hear Sherlock moving about the front entry hall as he continued his investigation there, and a few minutes later heard him climb the stairs to the first storey.

It took Lestrade just a few minutes to confirm Sherlock's observations about the brothers' Internet use, and a bit longer to locate insurance documents that named each brother as the beneficiary of the other's life insurance policy. He scribbled a few notes in his casebook, then took a look around the wreck of an office, but while Sherlock had castigated him often enough for 'seeing' rather than 'observing,' and while he'd spent years trying to develop a semblance of Sherlock's skill, nothing in the office led him to any further conclusions about the brothers or their habits, other than the self-evident fact that they were appalling slovens.

With the departure of the ME's assistants with the bodies silence settled over the house, and he easily made out Sherlock's footsteps overhead and the sounds of John moving about in the kitchen. It had not escaped his notice that while Sherlock had essentially ordered him to search the office, he had _asked_ John to take care of the kitchen. Nor had Lestrade missed the fact that while he'd provided specific guidance to Lestrade on what to look for, he'd done no such thing with John. Lestrade supposed that he should mind it, but the truth was that while he was proud of his career he'd made peace with the fact that he would never reach Sherlock's level of brilliance nor anything like it.

John, on the other hand, not only rated Sherlock's profound respect, but he'd made real inroads when it came to the sort of crime scene observations that Sherlock valued so highly. Lestrade liked and respected John, who, he was not too proud to admit, surpassed him in the matter of native intelligence just as Sherlock did. But then, John surpassed most of the population in the matter of native intelligence. It was just less apparent to people because he took no pleasure in drawing attention to the contrast the way Sherlock did.

Lestrade wondered whether Sherlock, normally so observant, realized the extent of John's influence on his career. Sherlock was as abrasive, infuriating, and off-putting as he was brilliant. Over time and under John's influence he'd planed away some of his more self-destructive personality traits, but alone it was not enough to overcome his maverick approach to crime solving. That had required John's more direct intervention.

Without John to run interference for him, Sherlock would have alienated the other half of London by now. John's considerable influence with the medical examiners and other crime scene professionals he and Sherlock encountered was a direct result not only of his own amply demonstrated competence, but of his scrupulous care of their professional standing, care which Sherlock would not have taken even if it occurred to him to do so. John's approach to those professionals was always self-effacing, always respectful of boundaries-in short, always the antithesis of Sherlock's acerbity and aggressive derision. In Sherlock's view, people should do a thing because it was the right way to solve a case, not because of how they felt about him personally. All the evidence in the world to the contrary would not shift him, and without John acting as the interface between Sherlock and so many of the people on whom he relied, Sherlock's career, Lestrade believed, would not be the spectacular success it was today. Likewise, Lestrade's case clearance rate would not be what it was, and he, too, often cited John Watson, MD as his authority rather than Sherlock, and with better results.

If he realized how essential he'd become to Sherlock's professional standing, John himself gave no hint. It _was_ obvious that he loved their work together and took pride in being able to make real contributions to their cases. While they'd always-and somewhat unexpectedly-clicked as friends, over time they'd become devastatingly effective working partners, as well.

Lestrade sighed: He was supposed to be theorizing about the case, not about his friends. He tucked the casebook back into this coat pocket and looked in on John in the kitchen. Sherlock joined them there a moment later, but he went straight for the washer/dryer combination in the far corner, opened the door, looked inside, and then dug through the basket of clothes that stood on the countertop over the appliance.

"You were right about their computer habits," Lestrade said, watching him, "and George had a £27,000 gambling debt. Their life insurance policies name each other as beneficiaries."

"Mm," Sherlock said, and turned away from the hamper. "John?"

"According to the neighbour they had all their groceries delivered, but there's nothing in the fridge or pantry that's very recent. In fact, from the state of the perishables I'd say they were about due for another delivery any day now. Also found this." He pointed to an open cabinet to the right of the sink, in which, among the clutter, stood four amber plastic druggist vials. "Betapace for George," he said, "and Norpace for Owen. Warfarin for both."

"Warfarin's an anti-coagulant," Sherlock said.

"Yeah. It's prescribed to prevent blood clots and stroke," John said. "The other two are heart medications that treat arrhythmia. It would be a pretty big coincidence for them both to die at about the same time of essentially the same heart condition, but I suppose it could happen."

Sherlock shook his head. "You know what I think of coincidences."

"Yeah." John frowned in thought and Sherlock said, "What?"

"Here's the thing," John said. "Disopyramide-that's the Norpace-reduces the force of cardiac contractions, right? At low doses it can reduce them by up to forty percent, but too much of it can reduce them completely. It's not hard to die of an overdose of the stuff."

"The ME would test for levels of that," Lestrade said.

"He should," John agreed. "Even if he didn't realize about the meds in here, he'll have access to their patient records. So, yeah. Not a bad murder weapon, though, because it wouldn't be hard to overdose accidentally, especially for someone on a regimen of multiple medications."

"Doesn't account for the kid passing out from something in the air," Sherlock said.

"I don't suppose that's a coincidence, either," John said.

Sherlock didn't answer; he was sniffing the air with a distant, distracted expression.

"What?" John said.

Sherlock crossed to the cooker, which stood in the corner closest to the side entryway, and on which stood a black-handled saucepan. "This," he said, pulling on another set of gloves.

"Yeah," John said, "I wanted you to see that, too. I couldn't make anything of it, but it smells..."

"Ooky?" Sherlock said.

"Yeah."

"'Ooky'?" Lestrade repeated, baffled.

"The neighbour boy. He described the smell in the house as 'ooky,'" John explained.

"You didn't touch this, did you?" Sherlock asked.

John held up his hands, palms out. "Nope. Just thought you'd think it was interesting."

Clearly he did. A half inch or so of blackened, apparently organic material adhered to the bottom of the pan. He used a long swab to pick up some of the residue, sniffed it gingerly, then dropped the swab into an evidence bag and handed the bag to Lestrade.

"What is that?" Lestrade asked.

Sherlock didn't answer. He opened each nearby cabinet door in turn and glanced at the contents, and only then turned back to Lestrade, but with a question of his own. "What can you tell me about this pan, Inspector?" he asked.

Lestrade sighed. "Well...I'd say someone was...I don't know...steeping tea, possibly? There's something stuck to the bottom of it. Can't tell what it is, but it looks burned. Could be tea leaves."

"And?"

Lestrade considered, but he was out of observations. "And..."

"Sherlock," John said.

Sherlock sighed. "George was using this saucepan," he said.

"George?" Lestrade repeated. "How the hell-?"

"George was the pipe smoker. Owen was the tea drinker," Sherlock said impatiently. "Try to keep up, Inspector. He started out steeping the contents of this pan, but once he was incapacitated that left the pan unattended and it boiled over. Look: You can see the water marks on the surface of the cooker and down the sides of the pan itself. Surely you've cooked rice or pasta to the point where the water boiled over and ran down the sides? That's what happened here. Eventually the water boiled off and the concentrated material at the bottom of the pan started to cook, then burn. One of the first emergency personnel on the scene would have turned the burner off, but if the neighbour children hadn't broken the window there's a fair chance no one would have found the bodies until the place burnt to the ground. There's no lid for the pan anywhere in sight because it's in here-" He pointed to the last cabinet he'd looked through "-so whatever is in this pan-"

"Is where the fumes came from?" John finished.

"It makes whatever's in this pan a good candidate for the contaminated air source," Sherlock said.

"Wait," Lestrade said. As usual, Sherlock was galloping far ahead of him, and as happened increasingly these days, John too seemed to have him at a disadvantage. "That...tea or whatever-it-is in that little saucepan killed two grown men?"

"It's a good candidate," Sherlock repeated.

"But wouldn't the fumes be...I don't know...too diffuse?" Lestrade asked.

"Now, yes," Sherlock said, "with the door standing open the way it was and the cooker off. But the house was closed up. The windows are painted shut, doors closed. It wasn't cold enough last night for the furnace to run if they kept the heat set much below twenty-seven, they were on a limited budget and deeply in debt, and in fact the thermostat is set to fifteen. There would have been very little in the way of ventilation, and with something toxic enough, yes, it's conceivable that the substance in this pan is responsible. Then the neighbour boy entered the house through that side door, remember? It communicates almost directly with this kitchen, obviously, and if this was the source of the fumes he would have been quite close to it. Just a few feet. If the contents of that pan _aren't_ the source of the fumes, what is? Even if the furnace had operated during the night, it wouldn't have done this morning, and John puts the time of death no earlier than mid-morning. Owen was overcome so quickly that he got no more than two strides from his chair. So: Putting the substance in the furnace would have heated it as effectively as a saucepan on a cooker, but that would-" He stopped abruptly. "Oh..." he whispered, and his eyes took on the thousand-yard stare that John knew so well.

"Sherlock?" Lestrade prompted.

"Oh, that's _gorgeous_," Sherlock whispered.

"What is?" Lestrade asked. "Sherlock!"

Sherlock shook himself and refocused on them with an effort.

"What about the furnace?" Lestrade asked.

"Furnace?"

"Yeah, you said something about the stuff in the pan being in the furnace?"

Sherlock frowned. "No, I didn't."

Lestrade held up the little evidence bag. "What _is_ this?"

"That's your sample," Sherlock said. He pulled on another pair of nitrile gloves, put the lid on the pan, plucked a plastic grocery bag from the clutter on the countertop, and wrapped it around the pan to tightly secure the lid. He dropped the arrangement into a second bag and tied it shut. "And this one is ours."

Lestrade had learned not to protest Sherlock's heterodox way with evidence: Somehow, he always contrived to pass muster in court.

"What about you?" John asked as Sherlock handed him the bag. "What did you find?"

"I'll show you," Sherlock said, and led the way to the front entry. There he stopped short of the doormat and pointed at the left side of the jamb, the side opposite the hinges. "Fibers," he said, and John and Lestrade leaned in to peer at them.

"Blue lint, looks like," Lestrade said.

"From a sweater. A rayon blend. Left by someone brushing against the jamb," Sherlock said. "No sweater of that color anywhere in the upstairs rooms, and nothing in the kitchen hamper."

"Too high up to be from anywhere much below shoulder-height of whoever left it," John noted. He looked from the lint to Sherlock, and said, "About your height, I'd say. The victims weren't anything like that tall."

Sherlock smiled. "Excellent," he said. "Anything else?"

John unlatched the front door, opened it, and looked out. Outside the darkness was complete, so he pulled his torch from his pocket, crouched down, and played the beam over the concrete landing. "Well," he said slowly, "I've got three sets of tracks. These two-" pointing "-are probably from the neighbour kids. The waffle sole's just a partial, but I'd say adult-sized. Wide...probably an adult male? Got one coming and one going, looks like. The kids' prints have messed it up a bit, so he must have been here before they were."

Lestrade glanced at Sherlock while John was speaking and saw, not for the first time, that Sherlock was watching John with a half-smile and a look of pride. John himself didn't notice; he was still focused on the front step. He stood up and clicked off the torch. "That's all," he admitted.

Sherlock took over. "John's wasting his talent at that clinic," he said to Lestrade. "You could do far worse than putting him on the Yard's payroll. Those blue fibers came from the sweater of an adult male no less than six feet tall who over-pronates. The victims were shut-ins. Had everything delivered, including their groceries and medications. The refrigerator and pantry are not newly stocked. What was the date on those pill bottles, John?"

"Both bottles of warfarin are dated yesterday," John said without hesitation. "The other two were filled on the twelfth, so about three weeks ago. Why?"

"Because it rained yesterday afternoon. By this morning the dirt on that landing would have been damp but not completely dried-damp enough to easily stick to someone's shoes. So the delivery boy from the druggist was in the house this morning, likely just before the deaths."

He took the torch from John. "Look," he continued, kneeling down and shining the light on the mat inside the door. "He stepped inside, stood on the mat. Same dirt."

Lestrade and John peered at the mat, but neither of them could see what Sherlock did. "Jesus, Sherlock," John said, still capable of being awed by his friend's skill.

"But anyone could have come by," Lestrade objected. "Why do you think the prints belong to the druggist?"

"Because the lint is blue."

"So?"

"Blue lint. From a blue sweater." He pointed to it. "The pharmacy that filled those prescriptions-"

"Was Boots," John said, remembering the label on the bottles.

Sherlock smiled "The store's livery is royal blue. Exact shade as the lint."

Lestrade was trying to follow. "Okay," he said slowly. "You think the druggist's delivery boy killed the vics?"

Sherlock looked at him like he was an idiot.

Lestrade shook his head. "The delivery boy _didn't_ kill them."

"Timing, Lestrade," Sherlock said knowingly. "Timing."

By now Sherlock had lost John, as well, but it was clear to John that he was well on his way to a solution: He didn't toy with Lestrade with that delighted gleam in his eye unless he was confident of his track.

Lestrade seemed to realize that as well. "You've already solved this, haven't you?" he said irritably.

"Very touching display of faith in my powers, Lestrade, but I wouldn't say that. I do think we've seen enough here, however. John?"

"Yeah, I'm good," John agreed.

"We need to get that to Barts," Sherlock said of the saucepan John still held. "I want to test that residue."

"Can't," John said. "Barts is off."

Sherlock frowned. "Off? What do you mean, 'off'? It's a hospital. How can it be off?"

"I mean their labs are closed. I heard about it this morning. One of the clinic nurses has a sister who works there. She had the day off because of a radiation leak or something. I overheard the nurse talking about it."

Sherlock gave a low growl of frustration. "Of all the incompetent-When will it be open?

"I don't know. Hang on, and I'll see if Molly knows anything. Monday afternoon," he reported, having ended the call with her. "That's her best guess. That's what Lewis told everyone in a memo, anyway. She says they're working round the clock to get things cleaned up, but apparently the cat litter they packed the stuff into caused a reaction."

"Cat litter."

"Yeah. Cat litter and nitrate salts. There wasn't that much material, but they packed it into a two-litre container with litter and the salts. The litter's supposed to absorb any liquid before they seal up the container and ship it out, right? But they switched from non-organic to organic litter last year, and they think that might have caused some kind of heat event that compromised the seals, and that released a bit of radiation."

Sherlock stared at him. "'A heat event.'"

"I don't know," John protested. "I'm not current on radioactive waste disposal. I'm just telling you what she said."

"Cat litter," Sherlock snorted. "That's _exactly_ the sort of thing that scientific illiterate Lewis would inconvenience me with."

"Yes, no doubt he had you in mind when he made the switch."

"Does it matter?" Sherlock cried irritably. "The result's the same!"

"It's just one more day," John said reasonably. "They won't even have the autopsies done by then. Wednesday, if you're lucky. You'll have to wait on that anyway. And don't worry," he added, "they discovered the leak almost immediately, so no one was injured. I know you meant for that to be your first question."

Sherlock gave a disgusted growl and turned to go.

"Hang on," Lestrade protested. "We might not have a 'how' until the autopsies are done, but what about a 'why'? What's the motive? They were just a couple of shut-ins, right? Why would someone kill them?"

"Maybe _because_ they were shut-ins," Sherlock replied cryptically.

"Online gambling debts might be a motive for murder," John offered.

"But if you're trying to get money from someone, why kill them?" Lestrade asked. "Makes it kind of hard to collect, doesn't it?"

"Because the killer didn't want to be repaid," Sherlock said simply. "Not in cash, anyway."

Lestrade frowned irritably. "What does that mean?"

But Sherlock turned and headed for the door. "Good night, Inspector," he called over his shoulder. "You already have everything we know. You go your way and we'll go ours, and we'll see who gets to the wire first."

ooooo

With the investigation into the twins' deaths at a standstill and Sherlock's swab experiment complete but awaiting the resumption of business hours at Imperial College London's DNA laboratory, they had Sunday free. They passed a leisurely breakfast together before John left Sherlock at the living room table with his newspapers and settled into his fireside armchair with the most recent British Medical Journal.

He'd been reading for some twenty minutes when his phone chimed with an incoming text. He withdrew it from his pocket and frowned. Harry.

"_Y dont u call round luv? Too good for me doctor? Mummys pet. Shed b disapointed." _

John glanced at his watch. Jesus Christ: Nine in the morning and she was already on her arse. He disgustedly dropped the phone onto the side table. He'd really hoped that she'd straightened out this last bout, after yet another girlfriend left her. She'd sworn up and down that she'd get herself back on track. Started going to AA meetings again; John had accompanied her to the first three for moral support, yet somehow his good intentions backfired. His presence only fed her sense of ill-use and grievance-she'd accused him of smug superiority, the farthest thing from his mind-so he stopped going. Shortly after that Harry stopped going. The phone chimed again.

_If I said I need Ur help would u come?_

John looked away. He tried to focus on the journal article, but when he'd read the same sentence a sixth time with no more comprehension than the first, he lowered the magazine and stared at the fire. She always said she needed his help, and he always went. And it never did any good. It just let her limp along, never getting any better, never getting real help or accepting real responsibility. Never really hitting bottom, never really scaring herself into permanent change. About two months ago he'd refused her for the first time. This was going to be the second.

_If my name was sherlock Homes U would of answered me by now_.

John's expression was grim. He'd never been able to explain his friendship with Sherlock to Harry, and after an attempt or two he'd quit trying. She didn't understand him; she certainly didn't understand Sherlock, and once he'd realized that it was a sore spot for her he'd stopped mentioning Sherlock at all, although that didn't please her, either. He knew that she read his blog posts about their cases because she often left comments there. She seemed to gain some sort of perverse delight in contrasting his relationship with her and his friendship with Sherlock, and then pitying herself.

_U always answer when he calls_. _U always will_.

John clenched his jaw. _Yeah, dammit_, he thought, _and he'd do the same, which is more than I can say for my own sister._

Another chime. _I now U luv him more than me. Thats cool tho._

Jesus Christ. John snatched up the phone and stabbed in a reply: _Yeah, well, he's not a pathetic drunk_.

"Don't."

John looked up in surprise. Sherlock had lowered the newspaper and was watching him intently. John had been so involved with the emotional turmoil of the texts that he hadn't noticed, and it took him a moment to understand. He blinked in confusion. "Don't what?"

"Don't send that text."

"Why the hell not? And-bloody hell, are you reading them from over there?" he cried.

Sherlock looked reproachful. "John. Even I can't read two millimeter text from fifteen paces."

"Then what the hell do you know about it?"

"I know that your sister is drunk at nine in the morning. I know that because no one else could text you on a Sunday morning-certainly none of your friends-and provoke that kind of response. You don't look that angry and turn that shade of red even when Mycroft texts you. Besides, when Mycroft texts you just look aggravated, not sad. You just received a series of texts from Harry, then, the first no doubt asking whether you'd come round. Probably misspelt, which is how you knew she was drunk. You glanced at your coat and considered, but then looked cross and rejected the idea, quite correctly, as enabling her. You were conflicted, however, so rather than turn the phone off you left it on and put it on the table where you could see it, knowing that she would send subsequent messages when you ignored the first. Each message was increasingly self-pitying, she probably unfavorably compared your relationship with her to the one you have with me, and she finally goaded you into a rude reply which, if you send it, will sever whatever tenuous ties you still have with her. Now. You have free will: You can send that text if you like. But I think you should reconsider." He shook out the newspaper and showed every sign of being about to resume reading.

John clapped his jaw shut. Sherlock had crammed a combination of trenchant observation, keen penetration, and infuriating complacency into a very few sentences, and John struggled over which attribute to assign primacy. Finally he said, very carefully, as though he were afraid of what he might say, "What do you care about her relationship with me?"

Sherlock lowered the paper. "I _don't_ care about her relationship with you. I care about yours, with her," he said. "I shouldn't, I know," he added, then said, in the tone of one quoting an authority, "'Caring is not an advantage.'"

John scowled. "Who the hell said that? Oh, wait. Let me guess. Mycroft." John was not happy about what he'd come to consider Mycroft's bad influence on Sherlock. As little as he knew about Sherlock's childhood, he knew him well enough now to realize that someone like Sherlock, with no use for children his own age, driven to learn and to know, craving intellectual stimulation and knowledge that could only come from adults-or an older brother-would be particularly susceptible to Mycroft's sort of cynicism. Mycroft would have reinforced Sherlock's own unfortunate conclusions about the dangers of emotionally investing in other people. No doubt he did so in all good faith, believing that he was doing Sherlock a favor, but John did not agree. The thought annoyed him at the best of times, but now, when he was already so ruffled, he found it perfectly infuriating.

"He used to say it when we were boys," Sherlock confirmed. "And a couple of times since."

"And you believe that?"

"I did," Sherlock said.

"But...?"

"No 'but.'"

"Sherlock, that's a load of rubbish and you know it." Sherlock looked surprised, and John said, "You care about a lot. You cared about Lestrade and Mrs. Hudson and me enough to jump off a building. You cared about M-" He stopped, looked away. He still couldn't go there.

"That's different," Sherlock said quietly.

"Caring's different from caring?"

Sherlock struggled to explain himself. "I used to think that's what Mycroft meant," he said. "It _was_ what he meant. He meant that caring about people doesn't help anything. Among other things it..." He took a breath, looked out the window.

"It hurts, sometimes," John said.

"_Yes_," Sherlock said, turning to glare at him. "Pain is nature's way of telling you that you're doing it wrong. Even a flatworm moves away from it. Only an idiot volunteers for it."

"Then you're an idiot."

"I suppose I am. But Mycroft's not."

"Of course he is," John cried, throwing up his hands in exasperation. "I swear to God, the two of you are the biggest frauds I know."

"Sorry?"

"You love your brother, Sherlock. You've spent your whole life looking up to him, taking his crap life advice to heart. As for Mycroft, the very first time I met him he tried to recruit me into helping him look after you. The fact that he's such a toffee-nosed bastard just makes it harder to tell that he means it, but he does. 'Caring's not an advantage.' What rot. Mycroft can't even follow his own advice, and you-" He stopped.

"Yes?" Sherlock said.

"You figured it out," John said, as though he'd just figured something out himself.

"What did I figure out, John?" Sherlock asked quietly.

John was suddenly quite sure that he didn't want to continue this conversation. His irritation had receded and now that he wasn't shooting from the hip he realized how deep he'd gone, what Sherlock had learnt and what it implied. He'd started this, however, and he had to finish it. "Whether you care personally about the victim of a crime-whether you care that he's robbed or dead-doesn't affect your ability to solve the crime. 'Caring's not an advantage' then, is it?"

Sherlock waited.

"You need evidence. Evidence to solve a crime. Evidence to feel an emotion. Evidence before you..." He paused again.

"Before I can have a friend," Sherlock finished gravely.

"You figured out the difference, but Mycroft...Mycroft never has."

"No," Sherlock said, and John thought he detected a hint of sadness in his voice. "I've tried to explain it to him, but..."

"But he's too smart to let you get through to him," John said with a smile. "Lucky for the rest of us you're the stupid one in the family."

That broke the tension. "And you're not smart enough to get through to Harry," Sherlock said.

"We suck at this," John agreed.

"What about that text?" Sherlock asked.

"That," John said, "I'm smart enough to take your advice about." He deleted the message and stood up. "I'm going for a walk. Coming?"

Still smiling, Sherlock shook his head. "Not today."

ooooo

As John reached for the alcove door a crash from Mrs. Hudson's flat froze him in place with his hand on the knob. The door to her place was open: Not unusual, as she liked to keep track of their comings and goings and, he suspected, to hear the comfortable sounds of their lives, although those devolved often enough into shouting. The crash, however, was unusual.

"Mrs. Hudson?" he called, tapping the open door and peering inside. "You okay?"

Mrs. Hudson was most definitely not okay. She was frantically, almost angrily, turning over the flat-patently searching for something. She glanced up and he saw with a shock that her face was streaked with tears.

"Oh, God," he said, starting toward her. "What's happened? What's wrong?"

"Oh, John," she said, making an obvious effort to collect herself. Her hands fluttered in confusion. "I'm sorry. No, it's nothing. Really. Nothing."

"Yeah, I can see that," he said, and steered her gently to a chair. He hurried to the kitchen for a box of tissues and handed it to her. "Tell me what's wrong," he said again, sitting down across from her.

She accepted the tissues gratefully, dabbed her eyes, blew her nose, and tried very hard to stop crying. "I think I did something very stupid," she sniffed. "I went to the market this morning."

John frowned. "Is that the stupid part?"

She plucked another tissue and wiped her eyes. "I was in the deli waiting for my number to come up and a man was there. Looking through the case.

"He was a young guy, nice-looking. The sort they used to call yuppies. Well, he looked a bit confused, so I asked him if he needed any help. He was shopping for his girlfriend, he said. He wanted to cook her a special dinner before he proposed, but he didn't know how to tell a loin from a cutlet, and we talked for a while-his girlfriend lives in Brighton and-well, you don't want to hear about that. Anyway, we chatted for a bit and I went off feeling like I'd done my good deed for the day. I went through the checkout lane but when it was time to pay I couldn't find my wallet. I could have sworn it was in my purse, but when you get to my age you can swear to a lot of things and be wrong. I felt like a complete fool, though, I can tell you that. Now I've been through the whole flat and can't find it anywhere.

"John," she said, looking earnestly at him, "I _know_ it was in my purse when I went out this morning. I took a coupon from it when I went through the dairy aisle, to make sure I got the right size package of butter. But the more I thought about it the more I thought, well, at my age sometimes...maybe..." Her tears welled up again in spite of herself.

"You are _not_ senile," John said firmly. "After you took the coupon out, where did you go?"

"To the deli. You want to save the perishables for last when you shop, you know," she said. "That way they spend as little time as possible out of the fridge."

"So you had it by the milk and when you finished with the deli it was gone."

She nodded. "I suppose so. I just didn't want to believe that I'd been such an old fool. I convinced myself that I'd left it here because...Because..."

"Because if you forgot it, it would mean that you weren't taken advantage of by a scumbag." He took her hand and gave it a squeeze, but there was a dangerous light in his dark eyes. He stood up, stepped to the open door, and directed a shout upstairs. "Sherlock!"

ooooo

Three hours later Mrs. Hudson stood at her kitchen sink, washing up after lunch. The front door slammed, then the inner door. _Noisy boys_, she thought affectionately. The door slamming wasn't followed by their usual thundering up the stairs, however. Instead she followed the sound of their characteristically confident steps through the foyer toward her flat. John tapped on the open door to announce them but Sherlock went right past him, through the sitting room and into the kitchen, where he poured himself a glass of milk and drank it off. He poured another, then ransacked the drawer where she kept the biscuits.

"Mrs. Hudson," John said, and held out one of the kitchen chairs for her. "Come and sit down."

She hesitated, glancing from one to the other-and noticed the fresh scrape over Sherlock's left eyebrow. "Oh, dear," she cried, "what happened?" She reached reflexively up but he tossed his head away like a horse and scowled.

"Sit down," he said indistinctly, his mouth full of biscuit.

John smiled reassuringly, and after another worried glance between them she did as she'd been asked. John sat across from her while Sherlock leant against the countertop and downed another biscuit. They both looked quite pleased with themselves.

"Not to keep you in suspense," John said, reaching into his coat pocket and presenting her wallet with a little flourish.

She caught it up with a cry of delight. "Where was it?" she asked, trying not to cry. She knew how much Sherlock hated tears. "How on earth did you find it?"

"Security footage," John said simply. "We told the manager we were helping the Yard-"

"Technically true," Sherlock put in.

"-and he was happy to help. He printed us up a couple of stills of the guy you talked to in the deli, one of Sherlock's homeless network recognized him, and she pointed us in the right direction."

She looked through the wallet as he explained. Everything was there-credit cards, cash point card, ID-and then some. "But...I don't understand. Where'd all this money come from?" She frowned as she counted the hundred-pound notes. "There's five hundred pounds in here."

Sherlock drained his glass. "A donation," he said.

She shook her head adamantly. "No. No, absolutely not. I won't take money from you boys. It's not right."

"You take our rent," Sherlock observed.

"It's a donation," John said, "from the degenerates who stole your wallet."

"I don't understand."

"No doubt," Sherlock said, then launched into his explanation. "They work as a team of two or three. Three, in this case. It's a common enough technique. One of them keeps an eye out for security and blocks the view of the video cameras if he can. One of them distracts the patsy-that would be you-with inane prattle that she's only too happy to engage in, and the third robs her blind. We had to overcome their initial reluctance to contribute," he added, ignoring John's wry look, "but John can be quite persuasive."

"So can Sherlock," John said, and looking from one to the other she realized that aside from Sherlock's scrape the knuckles on both their hands were bruised and the elbow of John's shirt was torn. It didn't take a consulting detective to realize the nature of the persuasion they had applied.

"They were happy to make amends," Sherlock said. "Eventually."

"We recommended that they avoid that store," John added. "It's a good idea to always keep your purse in sight, though, just as a policy."

"My boys," she said affectionately. "Thank you. But you shouldn't have risked yourselves like that just because I was foolish. If either of you had gotten hurt on my account I'd never forgive myself."

"Neither would I," Sherlock said.

"I'm sorry to have been so naive. And at my age," she went on. "But he seemed so nice, and he was so clean-not like a lot of young people you see these days."

Sherlock snorted. "He wouldn't be a very effective decoy if he looked like a serial killer and smelled like a monkey cage, now would he? That might raise a few red flags even in the sort of person willing to stand around yammering about chops with a complete stranger."

"Sherlock."

"Or then again it might not."

"_Sherlock_."

"It's okay, John," she said knowingly. "It's just his way of showing he cares."

"Ugh," Sherlock growled, and stalked off, darting two more biscuits into his pocket on the way.

Mrs. Hudson turned to John. "Thank you," she said again. "But I'm sorry to put you to so much trouble."

"Stop that," John said gently. "It's no trouble. You know we'll always be here for you."

ooooo

John usually but not invariably took his walks alone. Sherlock would accompany him on occasion, if he wasn't busy with a case, and if he could be bothered to bestir himself from the sofa, and if he found the weather to his taste, but the combination of circumstances presented themselves so seldom that for all practical purposes John's walks were solo affairs.

Today's errand for Mrs. Hudson had delayed him setting out, but he'd thoroughly enjoyed the process of retrieving her wallet (although he regretted her distress) and he knew that Sherlock had enjoyed it as well. "Just the two of us against the rest of the world," Sherlock had said to him once-a psychological confession if John ever heard one, but he, too, lived for that feeling that they were facing down life together, each as supremely confident in the other as he was in himself.

He'd enjoyed his walk, as well. The low, thick overcast from Saturday lingered, as did the fine mist, but today he'd detected the slightest promise of warmer temperatures to come, and that combined with his elation over their earlier adventure put real elastic in his step as he covered his regular route around Regents Park. Now, damp from the mist and flushed from his exercise, he looked forward to a hot shower.

Even with the flat's windows closed up he could hear the violin as he approached the front door. He hung his coat in the hall and edged quietly upstairs. The music was unfamiliar to him, and, apparently, to Sherlock as well. He was standing near the window, glaring at the music stand, determinedly working his way through a new solo piece. Probably the one he'd bought on Friday but hadn't had time to attempt until now.

He wasn't perfect, and even John's unrefined ear caught a false step here and there, an almost imperceptible hesitation now and again, but Sherlock approached new music like he approached life: with flair and fire. He was actually sweating with effort and concentration as he played and he gave no sign that he knew John was in the room. He reached a pizzicato section and John couldn't tell that he'd done anything wrong, but Sherlock suddenly stopped and dropped his arms to his sides with a cry of frustration.

"Jesus, Sherlock," John said, daring to breathe again.

Sherlock sighed. "I know. That was appalling."

"That was brilliant."

Sherlock glanced sharply at him, but he read nothing but sincerity in John's face.

"You really should play professionally," John said.

"Thought about it," Sherlock admitted. He laid the violin across the music stand and dragged a scrap of rosin over the bow. "Until Mycroft pointed out that orchestras by definition include other people. As do concert halls."

John smiled. "That the Paganini you bought? Caprice-something?"

"Number twenty-four." Sherlock eyed him as he slipped a cash point receipt into his wallet. "Drinks with Lestrade," he observed.

"Yeah," John said. "Tonight's the fifth anniversary of his divorce being finalized. He took it pretty hard at the time. Thought maybe it wouldn't hurt if he had a little company now." He turned and headed upstairs. "You're invited, of course," he called over his shoulder, not expecting an answer.

Sherlock in fact didn't answer, and the music started up again. Half an hour later John returned, showered and shaved, dressed in jeans and a somewhat drab blue and grey flannel shirt under a black sweater vest. The violin lay on the coffee table and the bow on the music stand. Sherlock was not to be seen. John shrugged into his haversack, scooped his keys off the cafe table, and broadcast in the blind. "I'm off," he called.

Sherlock emerged from his room. He'd traded the dressing gown for his overcoat and he was knotting his scarf as he came.

"I thought the lab was off until Monday," John said.

"Drinks," Sherlock said. "I'm going for drinks with Lestrade."

John stared.

"You said I was invited," Sherlock reminded him.

"Of course," John said, recovering. "Yeah. You are."

Sherlock looked at him narrowly. "What?"

"Nothing," John insisted.

Sherlock eyed him a moment longer. "Fine," he said. "Ready?"

ooooo

It was an easy walk to the Tiburon Pub on Edgware Road, near Speaker's Corner in Kensington Gardens and not quite a mile from Baker Street. They were a few minutes early, but so was Lestrade, and they met on the pavement across the street from the pub.

Lestrade took his cue from John and acted as though it was perfectly usual for Sherlock Holmes to go out for drinks, although to Lestrade's knowledge it had never happened before save for John's stag night, and that hardly counted.

The Tiburon was one of those dim, low-ceilinged places, with dark wood, gleaming brass, and cove lighting. Comfortable and snug. One of Lestrade's favorite pubs. They'd arrived early enough in the evening to easily secure a table at the far end of the room where a sort of raised platform or dais spanned the width of the place. A table-height wrought iron railing ran the length of the platform's edge, and at each end three steps led down to the pub's main level. It was a perfect vantage point for a cop, an ex-soldier, and a consulting detective.

Sherlock edged his chair around to put his back to the wall and give himself a view of the entire room. John sat to his outside and Lestrade across from John. As they removed their coats and gloves Lestrade noticed the state of their hands. Between that and the fresh scrape over Sherlock's eye they looked like they'd been in a brawl.

"What happened to you two?" he asked.

"We found a wallet," Sherlock replied absently, leaving him none the wiser. He glanced at John, but John just shrugged. Little things like that reminded Lestrade where John's loyalties lay.

"I'll start, yeah?" John said, and headed for the bar. An awkward silence fell-awkward for Lestrade, at any rate, although Sherlock appeared unaffected. Probably because he felt no need to make conversation. Against his better judgement, Lestrade did.

"Yeah, that case from Brent Terrace," he said. "With the twins."

Sherlock glanced at him, then returned to scanning the room at large.

"Any progress?"

"You mean since we established yesterday that we can't make any progress until Monday? No."

Lestrade sighed and reflected that he should have known better. Even after all this time, Sherlock had his limits. Lestrade had known him professionally for five years before John Watson arrived on the scene, and not once in that time had the detective demonstrated the least sign that he sought or was even capable of much above bare civility with another human being. He was not much changed now, but in those days the idea that anyone could deeply affect the icily aloof, unsociable Sherlock Holmes was unthinkable. Yet John had done so.

Sherlock was a very, very difficult man to reach, Lestrade reflected, and for a long time he'd puzzled over why. It wasn't until John came along that he understood. Most people, whether acquaintances, business associates, or even close friends and romantic partners, enjoyed each other on a superficial level for a variety of superficial reasons, some admirable, others less so. Sherlock could neither accept nor offer friendship on those terms. He took his values and his virtues deadly seriously, and that made him incapable of accepting overtures based on anything other than those virtues. He would _not_ be loved for being thoughtful of birthdays or a good conversationalist or fun at parties or for making people laugh or for smiling a lot. He would be loved for the purposeful use of his intelligence, for the unremitting exercise of his reason, and for his undeniable courage-or he would not be loved at all.

John succeeded where everyone else failed not merely because he offered admiration, respect, and friendship to Sherlock. Those things were important, but-and this was crucial-he didn't extend them unconditionally. He extended them-had offered them almost at once- in response to Sherlock's virtues, in response to the things of which Sherlock himself was proud. Lestrade suspected that was what had gotten Sherlock's attention: Not merely that his ego was assuaged, but that John's offer of friendship wasn't causeless, and therefore could be taken seriously by a man who took his life seriously.

After what seemed to Lestrade a very long time, John returned with two pints. Lestrade felt absurdly constrained by Sherlock's presence in this social setting, something that never happened when he met the detective professionally, but John took no notice of his friend and talked away without reserve, while Sherlock ignored them both, instead continuing to watch the pub patrons with an intent, searching expression.

When John asked after Lestrade's kids, however, Lestrade hesitated and glanced at Sherlock. John caught the look and waved his hand dismissively. "He's not listening."

Lestrade frowned. "But..." He made a 'he's right there' gesture.

John shrugged, eloquently conveying the concept, 'What can I say?'

"Sherlock," Lestrade said, testing. Nothing. Not a flicker.

John shook his head. "Seriously," he said. "He can't hear you."

"Does he do that a lot?"

"Define 'a lot.'"

Three pints later it was Lestrade's turn to pay, and he had just returned with their fourth round when Sherlock suddenly stood up and walked off without a word. They watched in surprise as he wedged himself into the crowd around the bar, mimicking the dozens of other patrons who were vying for the bartender's attention. He gave a nudge to the man next to him and pointed to something on the floor. The man glanced at Sherlock, then down at the floor, and bent to retrieve the item that Sherlock had pointed to, although John and Lestrade couldn't make out what it was. The man slipped the item into his coat pocket and moved off carrying a tumbler of amber liquid.

Sherlock returned to the table looking quite pleased with himself.

"What was that about?" John asked.

"You see that man I just talked to?" Sherlock said with a nod. The guy had found a seat in a corner by the front windows and was gulping down his drink, evidently trying to calm his nerves.

"Yeah."

"Keep your eye on him, Lestrade. Mid-level bank manager. He just murdered a woman. A prostitute at a guess, but just going on what I've seen so far I wouldn't insist on it."

They gaped at him with gratifying astonishment.

He explained with his customary rapid-fire, expository patter. "Noticed him the second he walked in," he said. "Sweating, for a start, although it's quite brisk tonight. Obviously not inebriated, but his hands shook when he flagged down the bartender. Could be ill, but he's neither pale nor flushed, so nervous, clearly. A closer look showed mud on the sides of his soles. Didn't arrive in a cab, so he walked here. Between this pub and the City mud that color and with that particular concentration of fine-grained sand can only have come from the immediate area around Market Mews and Shepherd Street. Not coincidentally, between there and the river are no fewer than eight brothels-shocking, I know, considering the pricey neighbourhood; you'd think there'd be more-with the nearest being in Shepherd Street. The man's clothes, watch, and tie pin make him a banker; their price makes him mid-level management at best, but still not likely to frequent alleys even in that neighbourhood. Fancy watch is cracked, by the way, probably during the struggle when he killed his victim but possibly when he wrestled the body into a skip."

Lestrade found his voice. "A skip?"

Sherlock nodded. "Went straight for the toilets when he walked in, but while he got his hands fairly clean what he can't see are the rust marks on the undersides of his coat sleeves: The rim of a skip made those marks when he reached in and deposited something heavy. Something so heavy that he could only just clear the rim as he disposed of it. Then there's the blood smear on the cuff of his right sleeve; might be from the victim but more likely it's from the nose bleed she gave him during the struggle. You saw me pickpocket his phone and then drop it, I'm sure: I needed to see the back of his neck."

John and Lestrade were three pints down and barely following. "Why?" John asked.

"Four parallel scratches. Deep ones, too, and acquired recently. Within the last hour. I could only confirm that once he bent over to pick up the phone. Three possibilities: One, she scratched him during the struggle. Two, she scratched him as part of the transaction. Some people like that sort of thing, you know, and will pay for it. Three, she scratched him during the transaction and he objected, which precipitated the murder. Difficult to say at this point, but no doubt their origin will come out during the interview. Either way, Inspector, you'll find her body in Market Mews, you'll find his DNA under her fingernails, and you might even find his fingerprints on her neck." He paused, looked from one to the other, and seemed vaguely disappointed when they didn't applaud.

"Why do you think the victim's a prostitute?" Lestrade asked at last.

"Lipstick and glitter," Sherlock said.

"Where did you see lipstick and glitter?"

"Lipstick-very particular shade of red, popular among sex trade workers-on the side of his neck, under the jaw, and glitter-" He stopped.

"What, on his shirt?" Lestrade guessed.

"Lower," Sherlock said.

Lestrade looked at John.

"He's been at the magazines again," John said.

"Well, there you are, Inspector," Sherlock said briskly. "That's easily enough to effect an arrest."

John and Lestrade were still staring at him. "An _arrest_, Lestrade," Sherlock repeated with a touch of his usual asperity.

Lestrade blinked. "Yeah, right," he said, recovering himself. "Right." He concentrated and tried to focus. He'd been drinking. He couldn't take someone in to the station while he was drunk, and was it even a good idea to approach a suspect after three pints?

Sherlock shifted impatiently and John said, "We'll give you a hand, yeah? Shouldn't be a problem between the three of us. You can call for backup," he added.

"Right," Lestrade said firmly, and reached for his mobile. "Backup."

ooooo

Sherlock and John watched from barstools at the window as Lestrade conferred with a uniformed patrolman. The banker sat handcuffed in the back of the squad car. Lestrade accepted a congratulatory handshake from the patrolman and returned, approaching them with a broad grin.

"Well, that wasn't how I expected the evening to end," he admitted.

Sherlock frowned. "How did you think it would end?"

Lestrade shrugged. "I dunno. Worst case was probably drunk-dialing the ex, I guess, but I'll take getting credit for catching a murderer over that any time. Are you sure you don't want-"

"No," Sherlock said firmly, and added disdainfully, "That's all I need: a reputation for slumming."

"Come on," John said to Lestrade. "Let's get you a cab."

They pushed through the crowd to the pavement and John waved a taxi over: Put up his left arm, regretted it, and switched to his right.

Lestrade opened the cab door, then paused. "Thanks, guys," he said again, and put out his hand.

"Any time," John said with a smile.

"Happy fifth anniversary of your divorce, Gary," Sherlock said.

John turned away with a groan.

"It's _Greg_," Lestrade sighed.

ooooo

"How's your arm?" Sherlock asked as they set off for home.

"Hm? Oh, just gave it a bit of a wrench. Doesn't take much. It'll be a bit sore for a while, that's all."

They walked in silence for a few blocks and then John said, "You did that on purpose."

"I do everything on purpose."

"I mean that's why you came along tonight, isn't it? To get Lestrade a collar."

Sherlock didn't answer, but he smiled in spite of himself.

"How'd you know-" John began.

"Oh, please," Sherlock said dismissively. "In a crowd that size? I'd be surprised if one of them _hadn't_ done something actionable." A pause. "Wasn't expecting a newly-minted murderer, I admit."

John smiled. "Well. You made Lestrade's day."

Sherlock drew himself up taller and shoved his hands into his coat pockets. "I caught a criminal," he said with dignity. "I can't help how Glen feels about it."

They turned the corner onto Baker Street. "It's Greg," John said.

ooooo

Monday's first stop was Imperial College London's DNA lab, where Sherlock left his swab

experiment for testing. From there they tracked down the waffle-soled, overpronating, not over-bright Boots delivery boy, who, with some gentle encouragement, referred to his delivery log and informed them that his stop at the Tregennis house occurred at 9:43 a.m., that George had signed for the order, and that Owen, while not making an appearance, had been heard to shout something to George about being careful not to overtip for the delivery, which had led to a general uproar, during which the delivery boy saw himself out of the house.

Sherlock seemed pleased by the information, but their arrival at Barts with the saucepan and other samples from the Tregennis house dampened his complacency when they were barred in the lobby from even accessing the third storey. The receptionist was profoundly sorry, but not only was the lab still closed, but it appeared that the earliest it would reopen was Wednesday morning.

"What happened?" John asked, while Sherlock fumed. "Wasn't it supposed to open this afternoon?"

"Well," the receptionist said, "they found another container that had a slightly damaged seal, so-"

"Another seal damaged by cat litter," Sherlock snapped.

"Sir, if you'd like to speak to the director-"

"Yes," Sherlock said.

"_No_," John said firmly. "That won't be necessary." He wasn't clear on just why David Lewis, the director of laboratories, loathed Sherlock so thoroughly, but the fact was that Lewis existed in a permanent state of one-sided war with the detective, and while Sherlock generally took no notice of the man's existence, the last thing John wanted was a confrontation while Sherlock was already so aggravated.

A confrontation was exactly what he got, however. The elevator doors opened and Lewis himself ambled out. He spotted Sherlock and John at once and approached, but he addressed the receptionist first.

"Any problems here, Donna?" he asked.

"No, sir," she said. "I-"

"Of course there's a problem," Sherlock snapped. "Radiation leaks, organic cat litter, delayed work, general idiocy. Idiocy being the proximate cause of the rest."

"Sherlock-" John began.

"Oh, I'm so sorry, Holmes. Did the lab closure inconvenience you? Donna, Mr. Holmes here doesn't like to be kept waiting. Please call upstairs and tell the hazmat team to open up immediately."

"Really?" she said.

"Of course not!" Lewis cried angrily, and turned to Sherlock. "The lab has been kept closed because the responsible policy in cases regarding safety is to exercise an abundance of caution."

"You hear that, John?" Sherlock said didactically. "When they start speaking in the passive voice you know you're listening to a bureaucrat covering his backside. The responsible policy is competence," he added, addressing Lewis. "Your lab safety practices wouldn't recommend themselves in the backwaters of a banana republic."

"Sherlock, just-" John tried again, but Lewis overrode him.

"I've really heard all I want to hear from you, Holmes," he said. "You're not a student and you're not an employee of this hospital. You're here on sufferance, and if you were as smart as you think you are you'd understand that and start showing a little humility."

"Oh, I understand," Sherlock said insolently. "I just don't care. I also understand that humility is for people who have something to be humble about, which explains your eagerness to promote it as a virtue."

"Sherlock," John said, "don't-"

"You know something, Holmes-"

"I know a very great deal," Sherlock began, and flicked his gaze over the director. "For example, I know that since being promoted to lab director your perfectly justified stress over your inadequacy for the role has worsened your eczema; I know that in addition to increasing your androgenic alopecia medication you'd be well advised to start a course of doxycycline-I understand the burning almost never goes off on its own-that you enjoy taking the submissive role in your relations with a certain subcategory of prostitutes, and that you are at this moment wearing women's underpants."

"Jesus Christ, Sherlock," John groaned.

Sherlock glanced at him and added a perfunctory amendment. "Not that there's anything wrong with that."

The receptionist laughed behind her hand and Lewis went from red to purple as Sherlock's observations ran their course.

"Well, _genius_, did you know that as of this second you're banned from these laboratories? I'd ban you from the building if I could-"

"If you could you'd be dean of medicine instead of idiot in charge of counting pipettes."

"-but I _can_ revoke your lab privileges. Donna-" turning to the receptionist, who hastily composed her features "-these men are not to have access to any lab or lab equipment in this hospital, as of this instant, and if you see them here again you will phone the police and have them removed as criminal trespassers."

"Doctor Lewis," John began. He was reasonably certain that Sherlock had well and thoroughly derailed this train, but in spite of that, and in spite of the fact that he personally disliked Lewis, he thought there might still be a chance to repair the damage. Lewis, however, was having none of it.

"I mean it, Watson," he snapped. "If either of you show your faces around here again I _will_ call the police. Now take your boyfriend and get out."

Sherlock caught John's arm just in time, and Lewis took a hasty step back. "No," Sherlock said. He didn't mind the confrontation for himself, but John didn't need an assault charge on his record.

"Get out of here, Holmes," Lewis cried, still backing away. "Both of you get out. If you're still here in two minutes I'll call the police."

ooooo

"Really, John," Sherlock began as they stopped on the pavement outside.

"Don't start," John shot back. "All you had to do was say 'fine' and leave. You can't tantrum them into opening a building that's contaminated with radiation. And anyway, Lewis wasn't any snottier than usual. Why couldn't you leave it alone?

"'Tantrum' isn't a verb."

"Sherlock, so help me...Look, just go home, will you? All we need is for him to call the cops."

"What are you going to do?"

"I'm going to see if I can talk to Mike," John said. "He doesn't like Lewis, and-"

"Nobody likes Lewis."

"Nobody likes you, either."

Sherlock smiled smugly. "True. But they hate me because I'm clever. They hate him because he's an idiot."

"Good. Congratulations. You win. Now _go home."_

ooooo

John circled the block to Little Britain Street, re-entered the building through the courtyard side, and took the stairs to the second storey, where Mike Stamford had his offices. Mike had been appointed Dean of Medicine the previous autumn, and unlike Lewis owed his advancement to a genial personality coupled with real ability. John saw him socially somewhat less often these days, but they'd managed lunch twice and drinks three times since his promotion.

Mike had always maintained a liking for Sherlock, and while Sherlock couldn't be said to reciprocate in any meaningful way he at least contrived to remember Mike's name and to regard him with a sort of benign indifference for which John had learned to be grateful.

Mike's honest face broke into a broad grin as his secretary showed John in. "John," he said, getting to his feet and reaching across his desk to shake his hand. "Come in, come in. Sit down. How've you been? How's the superhero business?"

"Good, Mike," John said, pleased to see his friend despite the errand he was on. "It's still better than working for a living."

"Still keeping a hand in at the clinic, though?"

"I'm down to one Saturday a month, now, but yeah. In fact, I was just there two days ago. Got Sherlock a case when one of my patients said she found her neighbours dead."

"Ah: Measles in the morning and murder after tea."

John grinned. "Seems to work out that way. What about you? Tired of the big office and comfy chair yet?"

"It's a trial, I admit," Mike sighed. "But we all have burdens to endure. Didn't think I'd see you up here this quickly, though."

"How do you mean?"

"The dust-up with Lewis."

John looked surprised. "How do you-?"

Mike dropped his voice an octave or two. "The great and powerful Dean knows all," he said portentously, then laughed at his own wit and at John's expression. "My secretary was passing by and heard most of what happened. She told me. That true about the ladies' knickers?"

John rubbed his eyes tiredly. "I don't know," he sighed. "Listen, I'm really sorry. Sherlock's been trying since Saturday to get this case resolved, and you know how well he copes with frustration. Champing at the bit and all that. He was kind of on edge. Yeah, okay, he's always on edge, but when he found out that he'd have to wait a bit longer things kind of went downhill. Neither of us handled it well, actually."

"And I'm guessing Lewis didn't break it to him gently, either. Rubbed it in his face a bit, did he?"

John shrugged. "A bit. Listen: What's the story with the hostility? I mean, Sherlock pisses a lot of people off, but it's like Lewis goes out of his way to antagonize him."

"Did you ask Sherlock?"

"Yeah, of course. Didn't get much of an answer, but I'm not sure he even knows. Once he puts someone in his 'Idiot' file he pretty much forgets about them. If he ever did know he probably doesn't remember now, and I _know_ he doesn't care."

Mike laughed. "That's got to drive Lewis to distraction. He's the kind of person who doesn't exist unless he can make other people think about him. But I can tell you exactly what happened between them, because I was there. Lewis was a grad student teaching a practical lab seminar. He had an application pending for an internship with Bartlesby-you remember? The dean at the time. Bartlesby's assistant was auditing the class that day, and I was there running an assay of some sort. Sherlock was on the far side of the lab doing his own thing-I didn't know who he was then, just saw him around the place a few times. I assumed he was a student, but someone told me no, he was at Cambridge or Oxford or something. He used to hang around to use the lab equipment. One of his professors had privileges here, and he kind of cribbed off of that until people just took it for granted that he'd be around.

"Anyway, he was off in the corner but he overheard Lewis going over the experiment. You know, laying out what equipment he was going to use, the expected reactions of the chemicals, things like that. If I recall, they were going to scale up a reaction mixture of some kind. When Lewis got to the proportions of the reactants and the solvent he was going to use, Sherlock looked up from what he was doing. 'You _could_ use two mils of solvent,' he said, 'or if you'd prefer a result that doesn't involve a smoking hole in the ground you could use the correct proportion of forty.' Not only was there not enough solvent by a factor of about twenty, but the magnetic stirrer bar wouldn't have been able to mix it thoroughly enough, so there would have been a real risk of overheating and, you know: boom."

"What happened? I mean, how did Lewis make that mistake?"

"Well, apparently he used software to calculate how to scale up the reaction mixture, but not the proportion of solvent. I never knew whether he did the solvent calculation by hand and got the wrong result, or forgot about it altogether, or what."

"Oops."

"Yeah, well, if Sherlock hadn't said something it would have been a very large 'oops' and a very large explosion, considering the amount of material Lewis would have been working with. The dean's assistant was really gracious about it-thanked Sherlock for speaking up, although of course Sherlock said he was just acting out of a well-developed sense of self-preservation-and tried to smooth it over for Lewis. Not very successfully, I'm afraid."

"And of course Sherlock applied his usual level of tact to the situation."

"Oh, of course," Mike said. "He had something to say about the practice of relying on software without thoroughly understanding principles. Something like, 'Any moderately dim monkey can be trained to pour crap into a flask, but when it's called on for actual comprehension you're likely to regret leaving anything in its hands other than a banana.'"

"Oh, God," John groaned. "That sounds about right."

"Doesn't it? Of course, Lewis always blamed Sherlock for the fact that he didn't get that internship."

"He should have thanked him for saving his arse."

"I know, I know," Mike agreed. "He's not that kind of a guy, though. I think even if Sherlock hadn't saved his bacon that day they'd have run into conflict sooner or later. A guy like Lewis gets his sense of worth from what other people think about him. Who do we know who's the exact opposite of that? Sherlock and people like Lewis will never get along. Unfortunately, Lewis managed to weasel his way into a position where he has authority. I'll have a word with him, though. Make sure he understands that Sherlock's off limits."

"Thanks, Mike. You know I hate to ask, but-"

"You didn't ask. Where's the fun in being supreme dictator if you can't help your friends, eh?" Mike said with a smile. "Besides, the work you and Sherlock do is important. He's not just some amateur playing around. Lewis didn't ban him for rules or safety violations. He banned him out of personal spite. And I'll tell you something else: I'd hate to see someone as brilliant as Sherlock get derailed by a spiteful snot like Lewis. It's not right. Even a genius needs someone to watch his back sometimes. That's you, by the way," Mike added. "And me, when I'm in a position to do something about it."

"You know," John said, "he knows human nature so well it's scary, sometimes, but a lot of it's academic. He just can't get his head around the idea that most people don't care about facts as much as he does. It's one of his blind spots, really. 'Is' versus 'ought,' and all that. He knows it up here-" pointing to his temple "-but he can't make himself act on it."

Mike nodded. "I'll talk to Lewis this afternoon. He's not going to like it, but that can be his problem. The one thing I can't do for you is get you in any sooner than Friday. There's just going to be too much catching up to do by the regular staff and students. There are limits even to a king's power, you know."

"No, Friday's great," John said sincerely. "And thank you. Seriously. I can't tell you how much I appreciate this."

"Don't give it another thought," Mike said. "Some things are more important than the fragile egos of lab directors." He paused, looking thoughtfully at John, then said, in a completely different tone, "You know, ten years ago when you took that flat together, I never thought that you'd end up best mates. To be honest I never thought that Sherlock knew how to have a mate. Or be one. He was absolutely hopeless. The only way to get any kind of reaction out of him was to leave him completely alone. God help you if you tried to make idle conversation with him. If you were lucky he'd just look at you like you had three heads. That's why we got on as well as we did, I suppose: Because I let him be. He seemed to appreciate it."

John smiled. "Did you think we'd kill each other?"

"No, no, not at all. I just knew that you were both looking for a flat share. I didn't really think much about whether you'd like each other. I suppose I figured you'd just leave each other alone. That seemed to be the only thing he ever wanted, and for all the friends you have, you're a bit of a loner yourself."

"A loner?"

"That's not a good word for it," Mike admitted. "I mean you're that independent. Sherlock's the cat who walks by himself, but so are you. It makes sense to me that two people that confident in themselves can get on as well as you do."

"Our landlady would tell you different."

"Oh, I suppose even a genius leaves toothpaste blobs in the sink. It's interesting, though, isn't it, what makes two people click? We almost never like someone who's really different from ourselves, deep down."

ooooo

Shortly after two John arrived home to discover that if anything Sherlock was in a more profound pet than when he'd seen him last: With his DNA results still pending and Barts off-limits he had the added irritation of boredom to contend with. John found him in the kitchen, rifling messily through the cabinets.

"What are you doing?"

Sherlock turned and assessed him. "Lunch with Stamford," he observed.

"Brilliant. I told you I was going to talk to him," John said dryly. "What are you doing?"

Sherlock eyed him more closely. "Cafeteria. Chili dog, no onions. Red gelatin." He sniffed. "Strawberry. You do know that gelatin is derived from animal scleroprotein?"

"What are you doing?" John asked again.

"Looking for the stick blender. What have you done with it?"

"Nothing, Sherlock, for God's sake. I don't use it. Have you checked the bread bin?"

"Hah," Sherlock said triumphantly, having looked in the bin.

"I got your lab privileges back," John informed him, "for which you're welcome, by the way. Friday mid-morning it's all yours."

"Friday?" Sherlock cried angrily.

"Yeah, Friday. They are running a hospital there, you know. They'll have work to catch up on. That's the earliest Mike could manage."

Sherlock opened his mouth to complain bitterly when his phone pinged with an incoming text. "Yesss," he cried, having glanced at it, and hurried to open his laptop.

"What?" John asked.

"ICL's done with the Shadow swab tests. They just emailed the results." He bent over the laptop, bouncing his knee and tapping his fingers impatiently on the table. "Come on...come on..._God_, why is everything so _slow_?" More silent fuming, but then he gave a cry of satisfaction. He printed the document, shoved it and a sheaf of notes into an accordion binder, and reached for his coat. "Coming?" he asked.

"Maybe. Where?"

"Scotland Yard. I know who the Shadow of Charleroi is."

ooooo

Detective Sergeant Sally Donovan was just thirty minutes into what promised to be a very tedious Monday afternoon shift of catching up on paperwork when the man she referred to as the Freak breezed into the squad room, followed by his bosom buddy John Watson. Always followed by John Watson. The Freak barged straight into Lestrade's empty office and dropped a thick file folder on the desk, but Watson paused in the doorway and looked back at her.

"Sergeant?" he said politely.

She knew he didn't like her. She knew that he blamed her for that business with Moriarty a few years back, and yet, unlike his psychopath friend, the Doctor was more often civil to her than not. It would have made her feel guilty if she didn't think he was such a fool, but although she was busy and stressed and didn't much like him, either, she gritted her teeth and made eye contact.

"Is Greg in?" he asked.

"Downstairs," she said curtly. "In the canteen." She paused, then added grudgingly and not very graciously, "Back in a minute."

"Great," Watson said. "Thanks." He turned to the Freak, asked if he wanted coffee, and when the answer came back negative headed off for the far corner of the squad room to get a cup for himself.

Donovan finished the report she'd been working on-the first of nine she hoped to process that day-printed it, and clipped it into a case folder. She carried it into Lestrade's office and dropped it into the in-box on his desk. The Freak was standing at the window with his hands clasped behind his back, staring out at who-knew-what. Not by the slightest flicker did he acknowledge her presence, although he must have heard her come in and she knew that he could see her reflection in the glass.

God, she hated that guy. Inhuman bastard. She wondered again at the contrast between him and Doctor Watson. Wondered how Watson could stand being in the same room with him, let alone share a flat. But the Doctor was devoted to the nutcase. Alone he seemed like a normal enough guy: Went for drinks with Lestrade, for example-but he was almost never alone. He was always with Holmes, that arrogant sod, and when she was feeling particularly benevolent she merely considered Watson's judgement to be seriously impaired. In less charitable moods she wrote him off as a masochistic sycophant, exclaiming over his friend's showy deductions like a teenaged fanboy while Holmes gloried in the adulation.

Back at her desk she tapped on the keyboard and brought up the next report, then stared at the screen unseeing: Tired, cross, and wishing she'd taken off sick. Detective Matt Sandberg, just arriving for his shift, strolled in from the hallway and, spying her, sauntered over: any excuse to avoid his own work. Generally she viewed Sandberg as a boring pest, but today he was a welcome relief from the even greater tedium of paperwork.

"Jesus, Sally," he said. "Make a late night of it, did you? You look like the dog's dinner."

"Thanks ever so, Sandy," she replied sarcastically. "Let me just make a note to give a rat's ass about your opinion."

Sandberg laughed. "No offense," he insisted. "You just look tired. You okay?"

"'I look 'tired'?" she repeated. "That your way saying I look like crap?"

"Okay," Sandberg shrugged good-naturedly. "You look like crap. What's up?"

She sighed. "Sorry. Yeah. I am tired. I was up all night with my brother. It was weird. He called me at, like, two in the morning all panicked because he was at the market and couldn't remember how he'd got there or how to get home or even where he lived."

Sandberg whistled. "Drunk?" he asked. "Can't handle the hard stuff?"

"He doesn't drink. No drugs, either, if that's what you're thinking. A bit of pot in secondary school, is all. You know. I was surprised he even went out to the store, because he's been complaining of being so tired all the time. Been doing all kinds of weird stuff lately, though. I told him to get himself checked out, but you know men are idiots that way. He'd rather keep tripping over lines in the pavement."

Sandberg started to say something in reply but Watson walked past then, coffee in hand, and settled in one of the chairs in Lestrade's office. Sandberg dropped his voice to a conspiratorial mutter. "What are Madman and Wonderboy after now?" he asked. "Here to register a complaint that someone stole their lube?"

Donovan snorted a laugh. "Come to ask for a new set of handcuffs," she said, feeling pleased for the first time that day.

"Next stop: Coco de Mer," Sandberg said, naming a boutique popular with London's bondage crowd.

"No, no. Freak Fetish," Donovan replied, naming another. "They're having a buy one, get one sale." They both laughed heartily at that, but Lestrade's return put an end to the merriment. He gave Sandberg the hairy eyeball as he passed and the detective ambled away, while Donovan sighed and returned to her work.

ooooo

"You here about the Tregennis case?" Lestrade asked as he sat down.

John shook his head. "Barts is still off," he said. "We can't get in there until Friday."

"Oh," Lestrade said, looking a bit disappointed. "Well, the autopsies are set for Wednesday, last I heard, so you should have preliminary findings by Friday. So what's up?"

Sherlock turned away from the window with a wolfish grin. "Remember the Shadow of Charleroi?" he asked.

Lestrade frowned. "That's...Interpol's big mystery, right? They found DNA from the same woman at thirty-odd different crime scenes in five countries, yeah? Can't for the life of them figure out her connection to them, if there is one."

"There is," Sherlock said. "Five countries. Thirty-nine crime scenes. And one woman's DNA was found at all of them."

"Right," Lestrade said. "Interpol just calls her 'the faceless woman.' Doesn't have the first clue what to make of it."

Sherlock looked triumphant. "I know. That's why _I_ made something of it. There's your answer, Inspector." He pointed to the file on Lestrade's desk. "The police agencies of each of those countries bought their evidence collection swabs from the same manufacturer. Swabs that are warranted to be sterile for medical purposes, but not free of human DNA. The 'faceless woman' is a factory worker, most likely, at the plant that manufactures the swabs. Find her and you'll find your DNA donor."

"Brilliant," John said in genuine awe, and Sherlock cast him an appreciative glance-his nearest approach to simpering.

Lestrade grinned. "I'm not going to ask if you're sure about this," he said.

"Good. I'd have to resent it. All the evidence you need is in that folder."

"Hang on," Lestrade said eagerly. "I have to tell the chief about this. He's going to have kittens."

"Kittens?" Sherlock frowned, but Lestrade was already dialing the phone. Sherlock edged closer to John. "John," he said.

"Yeah?"

"You're a doctor."

"And you're a detective. Glad we cleared that up."

"_As_ a doctor, tell me the first thing that comes to mind when I list the following symptoms."

John looked a bit puzzled but said, "Okay."

"Headache, confusion, balance problems, memory loss, disorientation, personality changes, fatigue."

John puffed out his cheeks and considered. "That covers a lot of ground," he said, "but 'first thing'? I'd say brain tumour. Why?"

ooooo

Donovan scowled when the Freak swept out of Lestrade's office as dramatically as he'd entered, looking like he'd just personally caught Jack the Ripper. _Conceited arsehole_, she thought. Watson was with him, of course, but he said, "I'll catch you up," and stopped before her desk. The Freak barely acknowledged him and disappeared down the hall.

She looked impatiently up at Watson. "What?" she demanded irritably. Somehow his manners annoyed her as profoundly as his friend's lack of them.

"Listen," he said, looking a bit awkward. "This is none of my business, and I'm sorry to butt in, but...Your brother."

She scowled angrily. "My brother? What about him?"

"He's been having headaches a lot lately?"

"How do you know that?"

Watson was more insistent. "Has he been having headaches?"

She glared at him, exceedingly suspicious, but finally said, "Yeah."

"Personality changes? Fatigue? Seems disoriented sometimes? Maybe balance problems?"

"Yeah. Yeah, what the hell-?"

"Well, it might not be anything, and I don't want to scare you, but-"

"What?" she demanded, because his words were having the opposite effect.

"Well, you might get him checked for a brain tumour." The stab of fear she felt then must have been evident on her face, because he hurried to add, "Sorry. I know it sounds scary, and I don't mean to upset you. The thing is, I know a great neurologist. Friend of mine. Here's his name and number." He handed her a scrap of notepaper from Lestrade's desk. "I'll call him, if you like, and make the referral official. He'll get you in this week." He smiled. "He owes me a favor or two."

ooooo

Four days later Donovan turned the corner onto Balvaird Place and wedged her official car into a space between the meat wagon and the criminalist's van. SOCOs milled about the periphery of the scene where a woman's body had been found earlier that morning. She hadn't heard many details about the case yet, but the Freak and his shadow were both there, so Greg, who had assigned this case to her, must have thought the circumstances were unusual enough to involve them. The thought made her scowl, but the fact was that she needed to talk to John Watson.

Fortunately he wasn't anywhere near Holmes at the moment. He was behind the police tape off to one side, conferring with Swanson, the ME. That was one more difference between him and the Freak, she reflected: He was standing with his gloved hands clasped behind his back, exuding a relaxed, friendly air, properly respectful of both the ME's professional jurisdiction and the fact that a woman had been murdered. Unlike Holmes, who was running around the corpse like a harrier around a rabbit warren while everyone else stood around watching him. Even from her vantage point in the car she could see that he was energized by the new puzzle. That's all crime victims were to him. Interesting puzzles. God, she hated that inhuman prick.

She used to almost pity the Doctor for his obvious attachment to the psychopath. She'd seen almost nothing of him after Holmes' faked suicide-without the Freak he had no reason to visit the Yard-but she'd heard enough from Greg to know that believing his friend dead had nearly destroyed him. It was inexplicable to her that he had so completely forgiven Holmes, but still more baffling was the deception itself, because she knew that on some level the Freak really cared for John Watson. If she hadn't seen the evidence herself she would never have believed it, but few things in her experience had surprised her so completely as the first time Sherlock Holmes indicated that he cared about the existence of anyone but himself.

In the early spring of 2011 the pair of them had been hanging around together for about a year when Lestrade invited them along for the capture of Lenny "Pongo" Boyd, a notorious scumbag who dabbled in everything from petty larceny to forgery, armed robbery, and, the Freak now claimed, murder. Greg thought it fitting that he and John be in on the arrest: Irregular in the extreme, to invite civilians along, but a pattern he'd established and obviously had no notion of breaking just because Donovan objected.

"Why's he called Pongo?" Watson had asked during the briefing.

"Because of the spots?" Lestrade suggested. Three wine stain marks on his face made Boyd instantly recognizable.

"He looks distinctly simian," the Freak said, and everyone stared at him.

Even Watson seemed confused by the remark. "What?"

"_Pongo_. The genus of orangutans."

General silence.

"He's _ginger_," Holmes said impatiently.

"I'm gonna go with the cartoon dog," Lestrade decided.

"What?" Holmes said.

"Pongo's a cartoon Dalmatian," Watson told him.

After a protracted foot chase they'd run Boyd to ground in a lane off Rotherhithe Street, where the Freak and Watson outflanked and cornered him in the angle where two residential buildings met. Lestrade, Donovan, and three constables, strung out behind, arrived seconds later.

Lestrade had the cuffs out and had ordered Boyd to put his hands on the wall when the fugitive suddenly uttered a shriek and dropped to the ground, thrashing violently, his eyes showing white, kicking, foaming, and grunting.

"Back off," Watson cried, motioning them away, and the police were only too happy to comply. "He's seizing. Stand clear."

Watson himself didn't move from where he'd been standing. The Freak glanced at him-even back then he would cede leadership to him if it was to do with medical matters-and held his ground as well, while Watson peered calmly and, Donovan thought, critically at the thrashing Boyd.

Lestrade spoke up. "Shouldn't we-I don't know-restrain him?" he asked without enthusiasm. "Won't he hurt himself?"

"No," Watson said firmly. "You can't help and you might get hurt. Better to wait it out."

Boyd's fit seemed interminable, but in fact it lasted just a minute or so, Donovan realized later. Eventually he collapsed and lay on his side, panting like a dog and looking disoriented.

Watson squatted down and peered intently into his face. Boyd's eyes looked crazed and unfocused, but eventually they lighted on the Doctor and he gasped, "What happened?"

"Anson," Lestrade said to one of the uniformed cops-she'd been an EMT before joining the Yard. "Give him a hand."

Anson stepped forward but Watson half-turned and put out his hand to stop her. "No, wait-" he began, and then Boyd struck.

He swung his left arm in a wide, backhanded arc, and Donovan realized with a shock that he held a knife. Watson saw the movement out of the corner of his eye and writhed away as hard as he could, but he was in an awkward position from which to evade the slash. With a sharp intake of breath he sat down hard on the asphalt.

The instant Boyd's hand emerged from beneath his jacket the Freak was in motion, and as Boyd reached the end of his swing Holmes was on him. He caught Boyd's knife arm, twisted it behind his back, and wrenched Boyd to his feet, dislocating his shoulder and slamming him face-first into the brick building so violently that his head bounced off it.

The Freak moved so fast that Donovan didn't know what he was doing until it was done, although Watson must have realized what he was about because his yell came even as Holmes went by him. The speed and feral violence of the attack shocked everyone into inaction-everyone except Watson, whose horrified shout of "_No!_" was the only thing that stopped Holmes from ramming the knife through the base of Boyd's skull and into his brain. He hesitated, his teeth bared and his knuckles white, and blood ran from under the knife as he paused with the tip pressed into the back of Boyd's neck. Boyd sobbed and wet himself.

Somehow, the Doctor kept his voice steady. "Sherlock," he said evenly. "Don't."

The Freak stood utterly still. "John," he said, and Donovan realized that it was a question: _Are you all right?_

"I'm fine. It's nothing. Don't hurt him," Watson said, and then added, "More."

Donovan couldn't take her eyes from the knife and she was terrified that at any second the psychopath was going to pith the guy like a frog, but Holmes didn't press the attack, although he didn't stand down, either. Watson gestured angrily to Lestrade, standing with the handcuffs dangling from his hand as though he'd forgotten he was holding them. "Greg, dammit," he cried. "Get in there."

Lestrade recovered himself and hurried forward. Only when he'd slipped the handcuffs onto Boyd did Holmes relent. He lowered the knife, took a step back. Lestrade half-carried the sobbing, terrified Boyd away and handed him off to a pair of uniformed cops standing gaping nearby.

Donovan heard him calling for two ambulances, but she was still standing frozen in place, staring.

The Doctor was bleeding pretty impressively from a gash in his right side, just above his belt, but he was sitting up and looking thoroughly pissed off about the whole situation. The knife slipped from Holmes' hand and he dropped to his knees beside him.

"John," the Freak said, and Donovan was astonished to see, as he pulled off his scarf and wadded it up, that his hands were shaking.

He obviously intended to use the scarf to stop the bleeding, but Watson caught his wrist and pushed his hand away. "Don't," he said irritably. "Don't make such a fuss. You've seen blood before."

He certainly had seen blood before, hundreds of times, with complete dispassion, but he looked stricken now. "Not-" he began, then stopped. _Not yours_. Somehow Donovan knew how that sentence would have ended.

"It's not as bad as it looks," Watson said crossly. "I told you. Superficial."

The Freak looked from Watson's face to his bloody shirt and then back, and Donovan read real fear in his cold, grey eyes. Fear and doubt. She'd have wagered a month's pay that he was incapable of either.

"But you're-"

"Sherlock. Mate," Watson said, and this time his voice was gentle. "Trust me. I'm a doctor." He smiled, and then, in a brisk, businesslike tone he added, "Come on. Put that back on before you ruin it, and give me a hand up."

The Freak hesitated. The doubt left his eyes, but not the worry. After a considering pause in which he studied Watson's face, he stood, stuffed the scarf into his pocket, and put out his hand.

"Ugh," Watson groused once he was up. "This shirt is ruined."

"Lestrade radioed for an ambulance," the Freak told him, and the Doctor balked.

"I don't need a damned ambulance," he cried, irritated afresh. "It's just a few stitches. We've got everything I need to do it at home."

"No. We're out of lidocaine."

"Dammit, Sherlock-"

"I needed it for-"

"An experiment. Yeah, yeah, yeah. Bloody hell."

Lestrade returned then, looking almost as worried as the Freak had, and said, "John, Jesus. Are you okay? Shouldn't you sit down?

Watson scowled. "Where'd you do _your_ internship, King's? It's just a scratch. How many times do I have to say it?"

"You see what he's like, Inspector," the Freak said. "Doctors make appalling patients."

"Yeah, well, come on," Lestrade said. "I'll give you a ride to A&E-and no arguments," he added firmly. "Sergeant," he said, turning to Donovan. "Do me a favor and cancel one of those meat wagons. Then get started processing Boyd, will you?"

"Yes, sir," she said. She trailed along in their wake as they made their way back to the cars.

"What tipped you off?" Holmes asked the Doctor as they walked. "The absence of pupil dilation?"

"That and wanting to know what happened. A and O immediately post-seizure is a dead giveaway."

"Of course," Holmes said, and after a pause added, "Well, there you are, you see? Your friends are wrong about me."

"Are they."

"I _am_ a good influence on you." That had what appeared to be the desired effect of making Watson laugh.

"How'd you come to that conclusion?"

"Your observation skills have improved tremendously."

"Oh, what, because I can spot a fake seizure?"

"Mm."

"Please," Watson scoffed. "I could tell a fake seizure before you were out of nappies."

The whole incident had remained vividly fixed in Donovan's memory, and not just because of the shocking contrast between Holmes' sudden, feral violence and his palpable fear for Watson. She remembered the day Holmes nearly killed the man who hurt John Watson because it was the first time the abrasive, aloof exterior that defined him to the world had slipped a little and given her a glimpse into the quiet understanding that existed between the two of them.

At the moment, however, the Freak looked entirely incapable of understanding anything on a human level as he crawled about the crime scene with his magnifying glass and an intent, rapt expression on his face. _Bastard_, she thought for the thousandth time. She sighed and got out of the car and headed toward Watson and the ME.

"Doctor Swanson," she said to the ME. "Good morning. Doctor Watson."

"Sergeant," they said.

She cleared her throat. "Doctor Watson. If you have a second?"

"Sure," Watson said. "Dave: Give me a minute?" He drew her off to one side and looked questioningly at her.

"Listen," she said self-consciously but with real feeling. "I really owe you. My brother saw your friend-the neurologist-and you were right: He has a tumour. He's scheduled for surgery in two weeks."

Watson smiled. "I'm glad he was able to help." He hesitated, then said, "Did he give you an idea of what to expect?"

"Yeah, yeah, he did. He said it was a...I'm sorry-medical terms-a menin..."

"Meningioma?" Watson said.

"Yeah. Something about brain membranes? He said it's benign and has a good recovery rate."

He nodded. "That's right. They originate in the membranes that cover the brain and spinal cord. Pretty common: About twenty percent of all brain tumours are meningiomas."

"Doctor Keith said it was caught very early, so he thinks there's a good chance of a complete cure."

"That's true," Watson agreed. "With early detection, surgical removal, and radiation therapy, and then following up with corticosteroids to reduce swelling after surgery, there's a very good success rate, long-term."

"That's what Doctor Keith said," Donovan replied. "I really, really have to thank you for what you did for my brother. If-"

"No, it wasn't me," Watson said. "It was Sherlock."

She stared at him. "The-I mean, Sherlock? _Sherlock_?"

Watson nodded. "He overheard you talking about it on Monday, when we were at the Yard about the Shadow case. He asked me what I thought of when I heard those symptoms, and I said, 'Brain tumour.' Sherlock's the one you need to thank. If he hadn't said something I'd never have known."

Donovan glanced with dismay at Holmes, still buzzing around the corpse. "Oh," she said. "Well...Thank you. Anyway. I'll..." She turned away from the Doctor and with a sense of dread made her way across the weedy empty lot to where the Freak was working.

"Holmes," she said determinedly. He ignored her, of course. "Holmes," she repeated.

"Busy," he snapped, not looking at her. Unable to look at her, because he was on all fours peering at blood spatter through his glass.

"_Sherlock_!"

That made him stare. He rocked back on his heels and looked up, then got to his feet, but he wasn't happy about it. "Well, Sergeant. I very much hope that whatever you're distracting me with now is more important than finding out who murdered this woman."

"Thank you," she blurted out, surprising him for the second time in the space of ten seconds. "I wanted to...Doctor Watson...I mean, he told me that you...He..."

She trailed off. Holmes hiked an eyebrow and was clearly on the verge of a cutting remark, so she quickly said, "I mean, thank you. For helping my brother. I don't know why you did it, but thank you."

He looked warily at her. His eyes flicked toward Watson, then back at her, and she knew that he was considering her conversation with the Doctor just now and weighing that against her awkward speech to him. Of course he'd noticed them talking. She could tell that he couldn't quite figure out how her speaking with Watson and her thanking him now were related, though, because he was a freak. As he continued to regard her skeptically she tried to keep her face composed: She didn't know how he did it, but she knew that he could read everything about a person, and she didn't want him to see her distaste for him. He saved her brother, after all. His eyes flicked to the Doctor again, like he was trying to decide what to do.

Finally he said, slowly, "You're...welcome."

There was no emotion in his eyes. No hostility, but no warmth, either. No follow-up questions about her brother. Nothing. He was indifferent to her existence, to her brother's existence, she was boring him, and she wanted to punch him. But he was the reason her brother was going to live.

He lifted his chin and regarded her imperiously. "Now if it's not too much trouble, Sergeant," he said coolly, "you're standing on a key piece of evidence."

"Oh..." she said lamely. "Sorry." He'd already dropped back to the ground, back to the blood spatter evidence, her presence forgotten, and she stepped away, giving him room.

She watched him work without really seeing him, and she wondered why he had helped her. Was he trying to put her in a position where she owed him something? To remind her that she'd done everything she could to destroy him, and that he had, however briefly, held power over her? Why else would he bother? He didn't care about her and still less about her brother. The only person he cared about was standing twenty metres away chatting with the ME.

A few minutes later Holmes finished his examination of the scene and walked off without a word. Not even a nod to all the SOCOs who'd been waiting on him. As usual. Walked off to rejoin his waiting friend. His only friend. Greg insisted that Watson had a humanizing influence on the maniac, but she didn't see it. To her he was the same icy, arrogant, condescending, robotic bastard he'd always been and always would be. The fact that he adored John Watson didn't change any of that.

Then again, he had saved her brother.

ooooo

Sherlock completed his inspection of the victim and the crime scene and made his way back to where John stood behind the police barrier.

"Got what you need, then?" John asked.

"Mmm," Sherlock said absently, scrolling through something on his phone.

"Molly called," John said. "The lab's back on schedule. Mostly."

"Took them long enough. We'll have to pick up the samples."

"Baker Street, please," John said as they climbed into the cab. He waited until Sherlock finished whatever he was doing with his mobile, then said, "Dave says that the Tregennis autopsies were both inconclusive. He officially listed 'unknown causes.'"

"That's it?"

John shrugged. "That's it. He said he'd change it, obviously, if you can point him to something more concrete. He suspects arrhythmia, personally, but doesn't know why it would hit both brothers at the same time like that, and since it's undetectable he can't confirm it anyway without something else to go on. Toxicology's going to take a while, but he can't really justify much beyond the basics without a reasonable suspicion, like signs of violence or someone having a clear motive that would point to murder. Which he doesn't have."

"_He_ doesn't."

"But you do."

"I told you: They were brothers."

ooooo

"Bart's Hospital," Sherlock said when John had retrieved the pot, the pipe, and the evidence bags and climbed back into the cab. As the cab set off he looked out the window and frowned. His long fingers drummed the arm rest.

"What?" John said.

Sherlock swung his gaze back to John. "At Balvaird Place just now."

"Yeah?"

"Donovan thanked me. Why did she say that?"

"Oh, that's just something people say when they feel grateful to another person. Don't worry. You'll probably never have to use it."

Wry look. "I meant in this particular context. Why was she thanking _me_?"

John looked surprised. "For helping her brother."

"Yes, you know, I have what would generally be considered a reasonably good memory, but I don't recall helping Donovan's brother. Where was I when this happened?"

"You told me about his symptoms. Monday, in Lestrade's office. I mentioned it to her. Got him an appointment with a neurologist I know, they found a tumour and scheduled the surgery. He should be fine."

Sherlock didn't look any less puzzled. "I don't understand. She should have thanked you."

"She tried."

"And?"

"And I told her that she should talk to you. If you hadn't mentioned the symptoms I never would have known. You're the one who helped him."

"Not on purpose," Sherlock cried, nettled.

John shrugged. "Yeah, well, let that be a lesson to you, then. If you don't want to go around saving people's lives-"

"I should Google what I want to know."

"You could do that. Or you could just be pleased that she'll spend the rest of her life feeling grateful to you."

"I don't _care_ how she 'feels' about me!"

John sighed. "I know."

"But you do."

"Yes!" It was John's turn to be exasperated.

Sherlock drummed his fingers with annoyance again. "She'll blather to everyone in a twelve mile radius that I did something 'nice' for her. How is that going to look?"

"Like you had a personality transplant," John said tiredly. "Want to go back and disabuse her of the idea?"

Sherlock leant forward to address the cabbie, but John said, "Sherlock. You saved her brother's life-accidentally," he added, as Sherlock opened his mouth to protest. "But you did it all the same. It's not a _bad_ thing. I wish-" He stopped, annoyed with himself.

"You wish you could save your sister."

"Of course."

"A brain tumour's not the same as-"

"I _know_."

Sherlock looked out the window again, but after a moment turned back to John. "Want me to do it?" he asked. "Apparently I can save siblings in my sleep."

John had to smile at that. "I don't care much about Donovan's opinion, either," he admitted, "but the good news is she hates you, so I really don't think she'll tell anyone. And there is a practical side: She might be easier to work with in the future. Look at Anderson, flinging department supplies at your feet."

"Swabs and gloves I can use," Sherlock said, not quite mollified. "What's Donovan got? Paperclips?"

"She will owe you one, Sherlock. Might be useful some day."

Sherlock eyed him narrowly. "Machiavel," he said.

"I learn from the best."

ooooo

They reached Barts a few minutes before noon. John talked Sherlock into using a side entrance-despite being under Mike's protection he thought it best to avoid Lewis if possible-but Sherlock still strode into the building wholly unconcerned with anything other than finding a laboratory in which to work. He rejected the first four as overcrowded-clearly there was still some backlog-but his fallback option, a room in an older section of the building and less popular with the students and staff, was unoccupied.

"Except for it lacking basic twentieth century equipment like a GCMS," he noted, looking through a few cupboards, "this will be ideal."

"No GCMS," John said regretfully. "No microscope that goes 'ping.'"

"It doesn't ping," Sherlock said didactically, "it chimes."

John sighed. "So we're doing this the old-fashioned way, then?"

"Have to," Sherlock replied. "We're testing for alkaloids," he added as he collected the equipment he wanted in a metal basket: stoppered brown bottles, pipettes, beakers, test tubes, a handful of glass rods, a box of glass slides. He set the basket on the table before John. "Specifically plant-based, and there are hundreds of them. As you know. We need to narrow it down."

"To what, dozens?"

"No. Two, for a start. Nicotine; that's a given, but it can double as the control, of sorts. For the rest: I'm not positive that the same compound killed both brothers, but considering the poisonous atmosphere it's probable. And considering the poisonous atmosphere, we need to be careful."

John nodded, but Sherlock fixed him with an urgent look. "I mean _careful_, John. Goggles, gloves-"

"Yeah, okay." John didn't want a lecture about lab safety.

"-and whatever you do, once you've handled a sample, whether it's come into contact with your gloves or not, _do not _touch the gloves to your bare skin."

"Fine."

"John-"

"Sherlock. I've got it. I've done this before. What the hell are we cooking here, anyway? What do you think it is?"

"Something very, very dangerous."

"Great," John muttered. "Fantastic."

"First we need to dissolve each sample in water," Sherlock went on, "in these." He arranged nine small beakers on the table. It won't take much." He demonstrated on the first sample, one of the old dottles, using an X-acto knife to obtain a tiny bit of material from within the evidence bag. He transferred this to a beaker, added distilled water, and stirred with a small glass rod. "Ten percent hydrochloric acid solution," he said, pointing to a stoppered brown bottle. "Add it drop by drop if the stuff doesn't dissolve in water alone until it's in solution. Be careful-"

"I've _got_ it," John said impatiently. "Gloves. Goggles."

"Be careful to keep the solutions as neutral as possible. We want the crystal precipitate to develop, and too much acid will tend to break it up and dissolve it."

"Oh."

Sherlock pitched in with the sample preparation, and they made short work of each specimen. Now it was time to create the reagents with which they would test the samples: Sherlock insisted on making fresh batches.

"You remember the formula for Mayer's?" he asked.

"Christ," John muttered, thinking. "That's...It's a one to one hundred ratio of mercuric chloride..."

"And distilled water," Sherlock said. "One point three-six grams of mercuric chloride, three grams of potassium iodide, and one hundred mils of distilled water."

"I knew that."

"Hm," Sherlock replied skeptically. "I'll take care of the sodium carbonate."

Once they'd finished creating the fresh reagents, Sherlock had further instructions. He pointed to the beaker of each dissolved sample in turn. "All three old dottles: Mayer's. First new dottle: Mayer's. Second new dottle: sodium carbonate. Tea cup: sodium carbonate. Tobacco mixture from Owen's pocket: Mayer's and sodium carbonate. Pan and pipe residue: one sample each with Mayer's and one each with sodium carbonate. Twelve solutions total."

"Got it," John said.

"I expect all the dottles and the pipe residue to show nicotine, obviously," Sherlock said. "As for the rest, I have my suspicions, but we shall see."

"What are you going to do?"

"I'm going to try to generate a little ookiness."

"How?"

"Very, very carefully."

ooooo

Chemistry was never John's forte-in spite of his best efforts it was the reason he finished with a class rank of fourth in medical school-but he'd necessarily relearned a lot and discovered a great deal more through his association with Sherlock. Sherlock's own knowledge of the science was both wide-ranging and profound. Chemical formulas, rules, and laws that John could only dimly recall having heard of, Sherlock knew intimately well. He was as thoroughly at home in the laboratory as he was in Baker Street, and there seemed no limit to his knowledge.

Goggles and gloves dutifully in place, John placed a single drop of the first alkaloidal solution on a slide and used a glass rod to add a small drop of the reagent. He clipped the slide into the arms of the non-pinging microscope and examined it for crystals. In this case, they formed almost at once. "Nicotine," he announced, writing down the result.

"Make sure you clean the glass rod," Sherlock said.

"Didn't use it," John replied. He was perfectly aware of the importance of not carrying traces of the crystals from one sample to another, but he was also aware that Sherlock was nervous about getting the correct results and therefore more inclined to micro-manage than usual.

Sherlock flicked on the vent hood fan, then the heating plate under the saucepan. The plate stood on a tripod to elevate it above the work surface inside the hood, and he lowered the clear curtain until it reached the level of the plate. In this way he could reach inside the vent hood to manipulate the pan while ensuring that he wouldn't inhale the deadly fumes he fully expected the pan residue to produce.

Generating the precipitate on the slides didn't take John very long. He'd subjected the samples Sherlock had indicated to the Mayer's reagent, and with the exception of the pan residue everything tested positive for nicotine, but that was to be expected. The first two dissolved samples that he treated with the sodium carbonate reagent-one obtained from the sample from Owen's pocket and one from the saucepan-produced no reaction, however. He felt unaccountably disappointed. "Sherlock," he said, looking up from the glass.

"Hm?"

"Can you have a look at this?"

Sherlock glanced over his shoulder at him.

"Want me to watch that?" John asked, indicating the pan.

Sherlock shook his head. "It's fine," he said.

"Have a look," John said, ceding his place at the table to him. Sherlock peered into the scope. "That's from the saucepan," John said. "The one off to the side is the 'Owen's pocket' sample. I don't know how long that reaction's supposed to take, but with the Mayer's the precipitate formed almost right away. Maybe you'll have better luck. I didn't want to muck it up by stirring; I wasn't sure how much of a nudge to give it."

Sherlock selected a clean glass rod, peered into the scope, and delicately stirred the solution on the slide. He paused briefly to give the agitation a chance to work when the lab's double doors banged open and David Lewis stormed into the room.

"What the _hell_ are you two doing in here?" he cried, already red in the face. "This is intolerable. I thought I made myself clear on Monday: Neither of you are permitted in these labs. You will leave at once."

Sherlock glanced up when the doors crashed open, but once he identified Lewis as the source of the noise he returned his attention to the scope.

John stepped around him, interposing himself between Sherlock and the director. "Doctor Lewis," he began in a reasonable tone, for all the good it did him.

"Get _out_!" Lewis cried again.

John fought the impulse to punch the man. "Doctor Stamford-"

"I don't give a _damn_ what Stamford told you," Lewis shouted. "He's not in charge of these labs. _I_ am, and _I_ am telling you to get out!"

"Busy," Sherlock said distantly, without looking up from the slide.

"I'm calling the police," Lewis snapped.

"Call them if you like," John said, still contriving to keep his temper in check. "Once it's all sorted the upshot will be the same. We've got permission from the Dean of Medicine, so-"

Sherlock gave the slide another gentle touch with the glass rod, and as he did so he caught his breath: Through the lens he could see, forming rapidly now, perfectly formed rosette-shaped crystals. The furious argument carried on without him, forgotten and unheard. Quickly he switched the saucepan solution for the other slide, and there they were again: the same rosette-like crystals beginning to form.

He raised his head from the scope but closed his eyes, trying to remember everything he'd seen at the Tregennis house, but other than what they'd found in the pan and the pipe there'd been nothing to indicate the source of the poison. Outside, then? No: Nothing in the garden matched...Yes! Yes, it _was_ in the garden! Just beginning to push clear of the flower bed mud. That's why he hadn't instantly recognized the plant for what it was: the deeply palmately lobed leaves had not begun to unfurl, and of course it also lacked the distinctive blooms that gave the plant one of its common names.

"Oh, I _love_ this!" he cried, turning to John, his eyes alight.

"You love this, do you?" Lewis shouted, quite beside himself. "You would, you psychopath. Anything to undermine my authority. Anything to sabotage my career. Well, why not? You've been doing it for twenty years!"

"Why are you still here?" Sherlock demanded. "I wasn't talking to you. Go away."

Lewis was apoplectic with rage. He turned on his heel and stamped out as furiously as he'd entered.

"John," Sherlock cried, turning to him and taking no notice of the director's departure, "John, forget about him, he's an idiot. I know what happened. It's aconite! That's what's in the pan and in the pipe. Look at the precipitate."

"Aconite?" John frowned. "I don't-"

"Devil's helmet," Sherlock explained. His words tumbled over themselves as his brain outpaced his ability to express himself. "Devil's helmet, after the shape of the flowers. Aconitum-wolf's bane-monkshood. A pseudo-alkaloid, diterpene class, lycoctonine type. It's incredibly dangerous; probably the most toxic plant known to man, for all it's a common garden flower. Even brushing against it with bare skin can kill. It was in the garden behind the house. I didn't recognize it because it was just starting to sprout, but it's absolutely distinctive when fully grown. The twins killed each other with aconite, John!" He couldn't stop grinning.

"Killed each other," John repeated, still not up to speed. "It wasn't accidental from the stuff on the cooker?"

"Yes!" Sherlock cried. "It was! That's what's so brilliant. Listen: The brothers were in debt. The death of either would leave the survivor with a life insurance payout that would clear the debt. But more importantly they _hated_ each other, and that's the key. It's too early in the year for them to have picked that aconite just sprouting in the garden. So where did they get it? Each of them independently picked aconite roots and leaves _last season_, dried them, and held on to them all this time until he decided to kill the other. And the best part-the _best_ part-they did it on the same day and accidentally _poisoned themselves in the process_. Fratricidal symmetry, John. Oh, I _love_ this. If we ever get to the GCMS we can confirm it, but that's just procedural at this point, a 'T' to cross for the police. It's aconite."

Although he'd followed Sherlock's explanation in only the sketchiest fashion, his friend's honest joy in his macabre discovery was infectious, and John found himself grinning as well. "Well," he said to Sherlock's back, for he had turned again to the saucepan in the fume hood, "that was the easiest low-tech lab work we've ever done. What do you want to do with the rest of this stuff?"

"No," Sherlock whispered.

John frowned at the non sequitur. "What do you mean, 'no'?"

Sherlock turned slowly to face him, his eyes wide with horror. He seemed frozen in place, unable to move, and it scared the hell out of John.

"Sherlock? What the hell-?"

Sherlock's throat worked, and with a supreme effort he whispered, "John. _Run_." Then his eyes rolled back, his knees buckled, and John only just had time to lunge forward and catch him as he fell.

The shock of taking Sherlock's weight staggered John and drove the breath from him, but as he inhaled he instantly understood what was happening. He coughed, ducked his head, and tried not to breathe as he half-dragged, half-carried Sherlock toward the doors. But Sherlock was heavy, they were only halfway to the exit, and as a vise tightened around his chest and his heart pounded furiously John knew real terror. The next breath he took would be his end, yet toxic as the atmosphere was, he would never make it all the way to the door without air and if that happened they were both going to die. He ducked his head as low as he could, took one last breath, and with all the strength it granted him he pushed Sherlock toward the doors.

ooooo

An alarm sounded inside the lab, followed instantly by others elsewhere in the building as the toxic air exceeded the emergency sensors' thresholds, and slowly the clangor pierced Sherlock's awareness. "John," he groaned. He coughed, drew in a great lungful of clean air, and opened his eyes. He was face down on the smooth cold floor of the Barts corridor and the taste of blood was in his mouth. "John?" he said again, and when there was no answer he raised his head-and his terror returned with his memory. "John!" he shouted, and lurched to his feet. He was alone in the corridor, but the lab doors were just ajar and he lunged for them, flung them wide, and almost fell over John where he lay huddled motionless against the doors.

Sherlock caught his wrist and dragged him clear of the lab, well out into the hall. "John!" he cried, patting his face. "John!" But John never stirred: not the slightest hint of movement or life. Sherlock fought down the urge to scream at him: He had to think. _Think_. _Think, idiot, use your brain. _Three things John always said you should do with an unconscious person. So simple even a genius couldn't screw it up, he said. ABC. The 'A' was for...God, _think!_ _Think! _Airway! Yes, airway. Airway, breathing, circulation. He slipped his hand under John's neck and tipped his head back, then had to still his own hoarse panting so he could hear: Held his breath until he was satisfied that John was breathing. Circulation: Two fingers pressed to the side of John's throat, and under them John's pulse raced furiously, unevenly. Aconite interfered with cardiac function, Sherlock knew, but he didn't know how, nor what it implied for John, but what was far, far worse, he didn't know how to help him, and not knowing made him frantic.

He did know that an unconscious person could aspirate vomit. He'd seen John place victims into what he called the recovery position, so gently he turned John toward him, onto his right side, bent his left leg for support, and slipped his hand under his neck again, to tip his head back. Checked his pulse again-no change; how long could his heart keep up that pace?-and now he was utterly out of ideas. "John," he cried, and shook him by the shoulder. "Wake up." His throat closed again, but this time it had nothing to do with any toxin. "I don't know what else to do, John. _Tell_ _me_." He patted John's face. "John, please. Wake up. Wake _up_."

"Sherlock," John groaned, and opened his eyes-and looked straight into Sherlock's pale, distraught face, nearly level with his own. "Sherlock?" Memory returned in a rush. "Jesus, Sherlock," he gasped, struggling dizzily to sit up. "Are you all right?" When Sherlock didn't answer he repeated the question, far more urgently: "_Are you okay? _Sherlock!"

Sherlock had been kneeling beside him, but now he sat down heavily, looking stricken and breathing like he'd run a race.

"Dammit, Sherlock, answer me!"

"Sorry," Sherlock whispered, almost inaudibly.

"What?" There were few things he could have said in that context to alarm John more thoroughly. "'Sorry?' About what?" He grabbed him by the shoulders and shook him roughly. "_Are you all right?_"

Sherlock blinked. He looked up and said vaguely, "Fine. I'm fine."

His haunted expression said otherwise to John, who took his hand and felt for his pulse. "You're bleeding," he noted as he counted.

Sherlock considered, ran his tongue gingerly over the inside of his mouth, dabbed at it with the back of his wrist. "I fell."

"You didn't fall," John said. "I pushed you." He let go of Sherlock's wrist-pulse strong, though elevated, but he attributed that to emotion rather than pathology: Sherlock was perfectly ashen. "Sorry about that, by the way. You're going to have a hell of a bruise here," he added, reaching up.

"Might have bothered to open the door before you threw me out of it," Sherlock said sulkily.

John sat back and considered him. "Plus side, purple and black's a good look on you."

Sherlock tried to smile in return, but abandoned the attempt almost at once. "I thought you were having a heart attack," he confessed. "Your pulse...I didn't know what to do."

"Nine nine nine would have been a good start," John said. He hitched himself around and leant against the wall, his legs straight out in front of him, and let his head tip back.

The first hospital personnel to respond to the alarm, fully encased in hazmat suits, pounded past them and into the lab.

"It wasn't a heart attack," John added. "Toxins that interfere with the sinus node can cause a very rapid or very slow heartbeat, but that's not the same as a heart attack. You can't know everything, Sherlock. I'm sorry to have to tell you that."

"You're not the first, I guarantee it," Sherlock said dryly, and looked worriedly at him. "Now? Are you all right?"

John considered that. His pulse was nearly back to normal and for the most part the room had stopped tilting. "Yeah," he decided. "Give me a hand up? See if we can find a doctor in this place."

Sherlock was on his feet at once and held out his hand. John glanced back at the lab, where the hazmat team milled. "We _are_ done here, I hope?"

"Yes," Sherlock replied categorically. "That's enough ookiness for one case."

"It's going to take an act of Parliament to get your privileges back this time," John said ruefully as they set out.

"No," said Sherlock, and a look of cold rage twisted his features. "Lewis shut the fan off and raised the curtain."

That stopped John in his tracks.

"Well, you never thought _I_ mucked up the experiment that badly," Sherlock cried.

John finally found his voice. "_Lewis_ did that?"

Sherlock gave an offended snort and started walking again.

"You apologized," John said, hurrying after him. "What was I supposed to think?"

"For underestimating Lewis's homicidal vindictiveness," Sherlock cried, "not for the aconite. Just how incompetent do you think I am?"

"Well, you couldn't diagnose a heart attack if my life depended on it."

"It didn't."

"Good thing."

This time it was Sherlock who stopped abruptly. He glared at John. "You thought I almost killed you and you were _okay_ with that?" he asked incredulously.

John shrugged. "You almost killed yourself, too," he said reasonably.

"No I-"

"Fine: I _thought_ you almost killed yourself, too."

"So you admit it."

"Yes! Yes, I admit it. Don't tell me that's news to you. When _haven't_ I been okay with it?"

Sherlock gave that some thought. "You always have," he decided.

"Damned right," John said. "Always."

They started down the hall again and Sherlock said, "Except for that one time with the golden glasses. And the red circle case. And-"

"Sherlock."

"Yes?"

"You're using words again."

ooooo

For the second time in the space of six days Detective Inspector Lestrade made an important collar thanks to Sherlock Holmes. Or, to be strictly accurate, he made the collar thanks to John Watson's insistence that Sherlock not pursue his own form of justice against lab director David Lewis.

Lewis's latest humiliation at Sherlock's instigation, like his last, took place in the very public lobby of Barts and caused at least as much of a sensation among the assembled staff and students as the detective's observation about Lewis's choice of foundation garments.

"David Lewis," Lestrade said in his dispassionate official voice, slipping the handcuffs onto the audibly weeping director, "I'm arresting you on two counts of attempted murder and assault with a deadly weapon. Get this guy processed," he added, handing him off to a pair of waiting uniformed cops. "I've got an errand to run."

"You see?" John said to Sherlock as they watched from the sidelines. "Letting the police handle it. Among other things, now you don't have to worry about where to hide the body."

Sherlock eyed Lewis with an unloving expression as he was led away. "I wasn't worried," he replied. "I know loads of places-"

"Yeah, okay. It was just an expression."

"You guys okay?" Lestrade asked as he approached them.

"Just a little ooky," John said.

"'Ooky,' eh? There's a lot of that going around. Come on: I'll give you a ride home. You said you solved the Tregennis case," he went on, once they were underway.

"Yeah, Sherlock figured it out," John said. "As usual." He glanced at his friend, but Sherlock was gazing out the car window and tapping his long fingers, not attending. "Sherlock?" John prompted.

"Hm?"

"The case?"

"Oh. Right." He sat up a little straighter and Lestrade thought he lacked some of his usual élan, but he laid everything out for the Inspector: The murder weapon; the acrimony between the brothers; their independent decisions to use aconite to kill each other, coincidentally on the same morning, George by brewing a tea of the stuff for Owen, and Owen by adulterating George's tobacco; their independent decisions to hoard last year's batch of devil's helmet; how Sherlock himself had missed recognizing the plant as it began to emerge from the ground.

"It's a beautiful murder weapon," Sherlock went on, warming to his topic. "It's one of the most toxic plants in the world, if not the most toxic, yet it's undetectable. As deadly as cyanide, but accessible to any gardener. Any careful gardener: Even brushing against it with bare skin can kill."

"It works by interfering with the heart's natural pacemaker," John added. "The sinus node. The Tregennis brothers already had questionable cardiac health, so it really was an excellent choice and I can't believe I just said that."

"It's true," Sherlock said. "It leaves no trace in the blood and the victim appears to have died of asphyxia, although it obviously leaves no physical marks, either. Nasty death, though: When it's given enough time to work it causes nausea, muscular and respiratory paralysis, convulsions, heart failure, and death."

Lestrade considered. "Why weren't there signs of that at the scene? There was no physical evidence to suggest any of those things."

"There would have been," Sherlock said, "if only one of them had picked that day to kill the other. But when George became incapacitated he couldn't tend to the saucepan. Owen didn't know anything about it-he drank all the tea that George put in front of him-so he had no idea anything was wrong until the fumes started to affect him. Meanwhile-"

"Meanwhile the tea worked on Owen, the tobacco worked on George, and the fumes killed them both accidentally," Lestrade finished. "Jesus."

"Turns out they were lucky, though," Sherlock said.

"How?"

"Dying from the tea and the tobacco would have been incredibly unpleasant. The fumes were the easy way out. It killed them before the ingested poison had a chance to metabolize and make things really ugly."

"I have a question," John said.

"Hm?"

"Owen nearly had time to get out of the room."

"Yes. He might have, too, if not for his heart."

"Why didn't we?"

"We were much closer to the source," Sherlock said simply, "and in a much smaller space. The fumes were far more concentrated in the lab than in that house, at least initially."

"Huh," John said.

"So," Lestrade said, "the delivery boy was never a suspect?"

"No," John said before Sherlock could answer, and then frowned. He knew that, but how? '_Timing, Inspector_,' Sherlock had said. John thought about Annora Roundhay kicking the ball through the door, about Mrs. Roundhay finding the bodies, the druggist's delivery, and what he knew was the window for time of death. He thought about Sherlock's observation that the point of the druggist's arrival was important. _Timing, Inspector._

Sherlock watched him work it out, and he didn't wait in vain. John said, "The delivery only mattered because Owen poisoned George's pipe when George answered the door."

Sherlock smiled to himself, and Lestrade grinned. "I really should put you on the payroll," he said. "But what about motive? Insurance payout, I suppose?"

"No," Sherlock said. "I told you: The primary motive wasn't financial repayment. Each of them wanted...Well, I suppose you'd call it emotional repayment. Payment for years of tolerating all the things he hated about his brother."

"The gambling and porn," John said.

"I doubt it," Sherlock said. "It's usually an accumulation of little things that make people homicidal."

"Oh. Like slopping water all over the bath mat."

"No. Bath mats are there for wet people to step on. More like putting the stick blender in the bread bin."

"I didn't put the blender in the bin!" John cried, while Lestrade rolled his eyes.

"Guys. Guys! Can we focus, please?" And when he had their attention he said, "So you knew it was a murder because they were brothers?"

"Of course," Sherlock said with a shrug. "That's why I took the case. Extrapolating merely from my own experience, I've probably spent hours thinking about the best way to poison Mycroft's smoothies. Aconite's not bad as those things go."

John and Lestrade stared at him.

"Oh, come on," Sherlock protested. "Surely everyone thinks about the best way to kill his sibling." Nothing. "Just me, then."

ooooo

Home to Baker Street, where if Mrs. Hudson had been listening she would have heard them climb the stairs with something less than their usual energy.

While Sherlock had admitted to a headache and John to some residual dizziness, they'd experienced no other side effects since they left the clinic and called Lestrade, and John was hopeful that that would remain the case.

They were steps from their landing when his hopes were ruined. Sherlock looked over his shoulder and asked him something about dinner, John felt a fluttering in his neck, and suddenly he was struggling to draw breath as his heart raced furiously against his ribs. He gripped the rail with both hands to keep from falling, squeezed his eyes closed, and dipped his head: Fainting on the stairway would be positively brilliant. Dimly he felt Sherlock's hand on his shoulder and heard his worried voice, but it was several seconds before he could safely answer.

"John," Sherlock repeated, sounding so distressed that John felt sorry for him. He shook his head-bad idea. "It's fine," he panted. "Fine. Just...give me a sec, yeah?" Already his pulse was steadying and he could breathe again. He straightened and opened his eyes, and for the second time that day looked straight into Sherlock's white, apprehensive face. "Just dizzy, a bit," he said with what he meant to be a reassuring smile. "I told you that might happen."

"Sit down," Sherlock ordered. "I'll call an ambulance." He rummaged for his phone. "We'll go to A&E."

"No." John put a restraining hand on his arm. Sherlock looked up sharply from the phone, met his eyes. He could detect John in a lie at a thousand yards, but John wasn't lying to him now. "It's okay, mate," he said kindly. "Really. Just give me a hand up, will you? I'd like to not face-plant between here and the living room."

Sherlock considered him doubtfully and decided that while John wasn't actually lying to him, neither was he 'fine.' He returned Sherlock's worried gaze steadily, however, and Sherlock thought that the dizziness that had staggered him had most likely abated. Mostly. He took John's elbow and steered him for the armchair.

John accepted the help, but the fact that he needed it was annoying. These residual symptoms weren't unexpected, as he'd told Sherlock, but they were unwelcome. He also knew that they were neither permanent nor life-threatening and were unlikely to recur. Sherlock knew nothing of the sort. After John sank into the chair he hovered.

"Go on," John said, gesturing at Sherlock's chair. "It's fine. All better now."

Sherlock settled on the edge of his chair but didn't take his eyes off John. "John," he began, but John held up his hand.

"It's to be expected, I told you," he said. "Tachycardia's more likely than not. It can cause dizziness, but at the levels we were exposed to it's transient. Already stopped. Probably won't happen again."

Sherlock didn't look as though he believed him. "I'm _fine_," John insisted.

Sherlock stood up determinedly and put his hand out. "Prove it," he said. "Give me your hand."

"No. Sherlock, for God's sake-"

"Your hand." John sighed resignedly and put his left hand out, palm up. Sherlock took his wrist and Mrs. Hudson walked in.

"Ooh-Oh, I'm sorry!" she cried, turning away in confusion. "Sorry! I just brought your mail up. I'll leave it here in the hall...I didn't mean to interrupt..." She trailed off and could be heard hurrying back down the steps, still apologizing.

Sherlock let go of John's hand, having satisfied himself on the question of his pulse, and they looked at each other.

"If you'd trust your doctor we wouldn't have that problem," John said reproachfully.

"Yes, we would," Sherlock said. He crossed the room and closed the door, then returned, still watching John closely.

"There's nothing wrong with my heart," John insisted.

"No," Sherlock agreed. "There isn't." He sat down again, but he was not still. He fidgeted and bounced his knee. After about a minute of that he said, "John-"

"It was _transient_!" John cried, his patience at an end.

"I'm sorry," Sherlock said, and John looked at him in surprise. Sherlock didn't apologize very often or very well, and now he'd done it twice in the same afternoon.

"What for this time?" John asked.

It was Sherlock's turn to look exasperated. "Is memory loss a side effect, too? You nearly died."

"So did you," John reminded him.

"Yes, well. Sorry about that, too. You don't cope well when I'm dead."

John laughed. "Lewis was the one who turned off the fan," he said reasonably. "This whole thing was his fault, not yours."

"Yes." Sherlock's eyes glinted dangerously. "But I should have known," he added after a short pause in which he savored a variety of extremely painful ways to kill the director. "A little reflection would have told me that the psychology of a man like that could easily lead him to-"

"Is this self-recrimination?" John asked.

"Yes," Sherlock said with a defiant lift of his head.

"Well knock it off."

"Sorry?"

"In our Earth culture saving someone's life doesn't require an apology. In fact, I'm pretty sure I should be thanking you."

"No. Do not," Sherlock said, moved as John had rarely seen him.

"Sentiment's not a side-effect of aconite, either," he said. "What's wrong?"

"Nothing. I..." Sherlock couldn't possibly say what was on his mind now. He was sorry he'd ever opened his mouth, so he shut it. "Nothing," he said again, and looked away.

"Okay..." John said slowly. Sherlock was nervously bouncing his knee and trying so hard to regain his impassivity that John almost laughed-and he might have, if the memory of his own terror for Sherlock's life were not so painfully vivid. He remembered opening his eyes to that anguished face, remembered the note of panic in Sherlock's voice and the tremor in his extended hand. The bravest man he knew. Now all these hours later Sherlock sat across from him fighting for his equanimity, and John knew why.

He cleared his throat and then, in exactly the offhanded manner he'd have used to ask whether Sherlock preferred Chinese or Italian for dinner, he asked, "So what do you think, then?"

Sherlock didn't look at him. "About what." Tense. Tapping.

"Think we're always going to do that?"

"What?"

"Scare each other half to death."

Sherlock didn't answer at once. He didn't look at John, but he stopped bouncing his knee.

For one of the few times in his life he didn't automatically ascribe the emotion he felt to the action of serotonin in his brain. He simply recognized it as gratitude-and he accepted it, because this was how John reminded him that he understood: With the psychological equivalent of a handshake, a subtle gesture that honored Sherlock's nature and his own. No one else had ever done that for Sherlock; no one else ever could. But it was John's inevitable way.

Sherlock didn't smile, but he looked at John and the tense light receded from his eyes. "Always," he said.


End file.
